literature review for a research proposal example

Literature Review Outline

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Literature Review. We all been there, especially those who are currently in high school or college. We get to review different types of literary pieces ranging from short stories , poem , and novels just to name a few. It can be confusing when you have a lot of ideas but you have no idea how to formulate them into one clean thought. It can also be quite frustrating if you have to start from the beginning or back to square one if you forgot a single part of the whole, but don’t worry, here are some literature review outline examples you can download to help you with your problems. Let’s check them out.

What is a Literature Review Outline?

A literature review outline is a structured framework that organizes and summarizes existing research on a specific topic. It helps identify key themes, gaps, and methodologies in the literature. The outline typically includes sections such as introduction, major themes, sub-themes, methodologies, and conclusions, facilitating a clear and comprehensive review of the literature.

Literature Review Format

A literature review is a comprehensive summary of previous research on a topic. It includes a systematic examination of scholarly article , book , and other sources relevant to the research area. Here’s a guide to structuring a literature review effectively:

Introduction

• Explain the purpose of the literature review.
• Define the scope of the review – what is included and what is excluded.
• State the research question or objective .
• Provide context or background information necessary to understand the literature review.
• Highlight the significance of the topic.
• Organize the literature review by themes, trends, or methodological approaches rather than by individual sources.
• Use headings and subheadings to categorize different themes or topics.
• For each theme or section, summarize the key findings of the relevant literature.
• Highlight major theories, methodologies, and conclusions.
• Note any significant debates or controversies.
• Critically evaluate the sources.
• Discuss the strengths and weaknesses of the existing research.
• Identify gaps or inconsistencies in the literature.
• Compare and contrast different sources.
• Synthesize the information to provide a coherent narrative.
• Show how the different studies are related to one another.
• Summarize the main findings from the literature review.
• Highlight the most important insights and their implications.
• Identify any gaps in the existing research that require further investigation.
• Suggest areas for future research.
• Discuss the overall significance of the literature review.
• Explain how it contributes to the field of study and the specific research question.
• List all the sources cited in the literature review.
• Follow the appropriate citation style (APA, MLA , Chicago, etc.) as required by your academic institution.

Research Literature Review Outline Example

I. Introduction Background Information: Provide context and background on the research topic. Explain the importance of the topic in the current research landscape. Purpose of the Review: State the main objectives of the literature review. Clarify the research questions or hypotheses guiding the review. Scope of the Review: Define the scope, including time frame, types of studies, and key themes. Explain any limitations or boundaries set for the review. II. Search Strategy Databases and Sources: List the databases and other sources used to find relevant literature. Keywords and Search Terms: Detail the specific keywords and search terms employed. Inclusion and Exclusion Criteria: Describe the criteria for including or excluding studies. III. Theoretical Framework Relevant Theories: Introduce and explain the key theories and models related to the research topic. Application of Theories: Discuss how these theories provide a foundation for understanding the literature. IV. Review of Literature Thematic Organization: Organize the literature into themes or categories based on common findings or approaches. Example Structure: Theme 1: Impact of Rising Temperatures Summarize key studies and findings. Compare and contrast different research approaches. Theme 2: Changing Precipitation Patterns Highlight significant studies and their results. Discuss any conflicting findings or perspectives. Theme 3: Socioeconomic Factors Review literature focusing on socioeconomic impacts. Analyze how these factors interact with environmental changes. V. Critical Analysis Strengths and Weaknesses: Evaluate the strengths and limitations of the reviewed studies. Discuss the reliability and validity of the methodologies used. Methodological Critique: Assess the methodologies for potential biases and gaps. VI. Discussion and Synthesis Integration of Findings: Synthesize the findings from the literature into a cohesive narrative. Highlight common themes, trends, and gaps. Research Gaps: Identify areas where further research is needed. Suggest potential future research directions. VII. Conclusion Summary of Main Findings: Summarize the key insights and conclusions drawn from the literature review. Importance of the Topic: Reiterate the significance of the research topic. Implications for Future Research: Outline the implications of the findings for future research. VIII. References Citation List: Provide a complete list of all sources cited in the literature review. Follow a specific citation style (e.g., APA, MLA, Chicago). IX. Appendices (if applicable) Supplementary Material: Include tables, charts, or detailed methodological information that supports the review but is too extensive for the main text.

Thematic Literature Review Outline Example

I. Introduction Background Information: Provide context and background on the research topic. Explain the importance of the topic in the current research landscape. Purpose of the Review: State the main objectives of the literature review. Clarify the research questions or hypotheses guiding the review. Scope of the Review: Define the scope, including time frame, types of studies, and key themes. Explain any limitations or boundaries set for the review. II. Search Strategy Databases and Sources: List the databases and other sources used to find relevant literature. Keywords and Search Terms: Detail the specific keywords and search terms employed. Inclusion and Exclusion Criteria: Describe the criteria for including or excluding studies. III. Thematic Review of Literature Theme 1: Impact of Rising Temperatures Summary of Key Studies: Summarize the findings of major studies related to rising temperatures. Example: “Smith et al. (2020) found that increasing temperatures have led to a 5% decline in crop yields globally.” Comparison of Research Approaches: Compare different methodologies and approaches used in the studies. Example: “While Jones (2018) used a longitudinal study, Brown (2019) employed a cross-sectional analysis.” Theme 2: Changing Precipitation Patterns Summary of Key Studies: Highlight significant studies and their results. Example: “Lee and Wang (2021) reported that altered precipitation patterns have increased the frequency of droughts.” Discussion of Conflicting Findings: Discuss any contradictory findings or differing perspectives. Example: “Contrary to Lee and Wang, Garcia (2020) found minimal impact of precipitation changes on crop health.” Theme 3: Socioeconomic Factors Summary of Key Studies: Review literature focusing on the socioeconomic impacts of climate change. Example: “Davis (2017) highlighted the disproportionate effects on small-scale farmers.” Analysis of Interactions: Analyze how socioeconomic factors interact with environmental changes. Example: “Economic instability exacerbates the vulnerability to climate impacts (Green, 2018).” IV. Critical Analysis Strengths and Weaknesses: Evaluate the strengths and limitations of the reviewed studies. Example: “Many studies provide robust data but often lack consideration of regional variability.” Methodological Critique: Assess the methodologies for potential biases and gaps. Example: “There is a notable reliance on regional data, limiting the generalizability of findings.” V. Discussion and Synthesis Integration of Findings: Synthesize the findings from the literature into a cohesive narrative. Example: “The review indicates a clear trend of climate change negatively impacting agriculture, though the extent varies regionally.” Identification of Gaps: Identify areas where further research is needed. Example: “There is a gap in research on adaptive farming practices and their effectiveness.” VI. Conclusion Summary of Main Findings: Summarize the key insights and conclusions drawn from the literature review. Example: “Overall, rising temperatures and changing precipitation patterns are significantly affecting agricultural productivity.” Importance of the Topic: Reiterate the significance of the research topic. Example: “Understanding these impacts is crucial for developing effective adaptation strategies.” Implications for Future Research: Outline the implications of the findings for future research. Example: “Future research should focus on adaptive measures to mitigate the adverse effects on agriculture.” VII. References Citation List: Provide a complete list of all sources cited in the literature review. Example: Smith, J. et al. (2020). Impact of Rising Temperatures on Global Crop Yields . Journal of Environmental Studies, 45(3), 234-250. Lee, S. & Wang, H. (2021). Precipitation Patterns and Drought Frequency . Climate Research Journal, 29(2), 98-115. VIII. Appendices (if applicable) Supplementary Material: Include tables, charts, or detailed methodological information that supports the review but is too extensive for the main text. Example: “Appendix A includes a table of regional crop yield changes from 2000 to 2020.”

Literature Review Outline Example in APA Format

1. Title Page Title of the Review Author’s Name Institutional Affiliation Course Name and Number Instructor’s Name Due Date 2. Abstract Summary of the Literature Review Brief overview of the main points Research question or thesis Key findings Implications 3. Introduction Introduction to the Topic General introduction to the subject area Importance of the topic Purpose of the Review Specific objectives of the literature review Research Questions or Hypotheses Main research question(s) or hypotheses guiding the review Organization of the Review Brief outline of the structure of the literature review 4. Theoretical Framework Relevant Theories and Models Description of key theories and models relevant to the topic Application of Theories Explanation of how these theories are applied to the research problem 5. Review of the Literature Historical Context Background and historical development of the research topic Current Research Summary of recent studies and their findings Methodologies Used Overview of research methods used in the studies Themes and Patterns Common themes and patterns identified in the literature Contradictions and Gaps Conflicting findings and gaps in the literature 6. Critical Analysis Evaluation of Key Studies Critical analysis of the most influential studies Strengths and limitations of these studies Comparison of Different Approaches Comparative analysis of different perspectives and methodologies 7. Synthesis of Findings Integration of Theories and Results How the findings integrate with the theoretical framework Overall Trends Summary of the major trends in the literature Gaps in the Research Identification of gaps and areas for further research 8. Conclusion Summary of Main Findings Recap of the most significant findings from the review Implications for Future Research Suggestions for future research directions Practical Applications Implications for practice or policy 9. References Complete Citation of Sources Proper APA format for all sources cited in the literature review 10. Appendices (if necessary) Additional Material Any supplementary material such as tables, figures, or questionnaires

Literature Review Outline Templates & Samples in PDF

1. literature review template.

3. Literature Review Outline Template

6. Preliminary Outline of Literature Review

7. Literature Review Outline Example

8. Printable Literature Review Outline

Types of Literature Review

A literature review is an essential part of academic research, providing a comprehensive summary of previous studies on a particular topic. There are various types of literature reviews, each serving a different purpose and following a unique structure. Here, we explore the main types:

1. Narrative Review

A narrative review, also known as a traditional or descriptive review, provides a comprehensive synthesis of the existing literature on a specific topic. It focuses on summarizing and interpreting the findings rather than conducting a systematic analysis.

2. Systematic Review

A systematic review follows a rigorous and predefined methodology to collect, analyze, and synthesize all relevant studies on a particular research question. It aims to minimize bias and provide reliable findings.

3. Meta-Analysis

A meta-analysis is a subset of systematic reviews that statistically combines the results of multiple studies to arrive at a single conclusion. It provides a higher level of evidence by increasing the sample size and improving the precision of the results.

4. Scoping Review

A scoping review aims to map the existing literature on a broad topic, identify key concepts, theories, and sources, and clarify research gaps. It is often used to determine the scope of future research.

5. Critical Review

A critical review evaluates the quality and validity of the existing literature, often questioning the methodology and findings. It provides a critical assessment and aims to present a deeper understanding of the topic.

6. Theoretical Review

A theoretical review focuses on analyzing and synthesizing theories related to a specific topic. It aims to understand how theories have evolved over time and how they can be applied to current research.

7. Integrative Review

An integrative review synthesizes research on a topic in a more holistic manner, combining perspectives from both qualitative and quantitative studies. It aims to generate new frameworks and perspectives.

8. Annotated Bibliography

An annotated bibliography provides a summary and evaluation of each source in a list of references. It includes a brief description of the content, relevance, and quality of each source.

9. Rapid Review

A rapid review streamlines the systematic review process to provide evidence in a timely manner. It is often used in healthcare and policy-making to inform decisions quickly.

10. Umbrella Review

An umbrella review, or overview of reviews, synthesizes the findings of multiple systematic reviews on a particular topic. It provides a high-level summary and identifies broader patterns and trends.

Purpose of a Literature Review

A literature review is a critical component of academic research, serving multiple important purposes. It provides a comprehensive overview of existing knowledge on a topic, helps identify research gaps, and sets the context for new research. Here are the key purposes of a literature review:

1. Summarizing Existing Research

A literature review summarizes and synthesizes the findings of previous studies related to a specific topic. This helps researchers understand what is already known and what remains to be explored.

2. Identifying Research Gaps

By reviewing existing literature, researchers can identify gaps or inconsistencies in the current knowledge. This allows them to pinpoint areas where further investigation is needed and justify the need for their research.

3. Providing Context and Background

A literature review sets the context for new research by providing background information. It helps readers understand the broader landscape of the topic and how the current study fits into it.

4. Establishing the Theoretical Framework

Literature reviews often involve discussing various theories and models relevant to the topic. This helps establish a theoretical framework for the research, guiding the study’s design and methodology.

5. Demonstrating Researcher Knowledge

Conducting a thorough literature review demonstrates that the researcher is knowledgeable about the field. It shows that they are aware of the key studies, debates, and trends in their area of research.

6. Justifying Research Questions and Methodology

A literature review helps justify the research questions and methodology of a study. By showing how previous studies were conducted and what their limitations were, researchers can argue for their chosen approach.

7. Avoiding Duplication

Reviewing existing literature ensures that researchers do not duplicate previous studies unnecessarily. It helps them build on existing work rather than repeating it.

8. Highlighting Key Findings and Trends

A literature review highlights significant findings and trends in the research area. This helps researchers understand the development of the field and identify influential studies and seminal works.

9. Informing Practice and Policy

In applied fields, literature reviews can inform practice and policy by summarizing evidence on what works and what doesn’t. This helps practitioners and policymakers make evidence-based decisions.

10. Facilitating a Comprehensive Understanding

Overall, a literature review facilitates a comprehensive understanding of the topic. It integrates various perspectives, findings, and approaches, providing a well-rounded view of the research area.

Components of a Literature Review

A well-structured literature review is essential for providing a clear and comprehensive overview of existing research on a particular topic. The following components are typically included in a literature review:

1. Introduction

The introduction sets the stage for the literature review. It provides background information on the topic, explains the review’s purpose, and outlines its scope.

Example: “Over the past decade, research on climate change’s impact on agriculture has proliferated. This literature review aims to synthesize these studies, focusing on the effects of rising temperatures and changing precipitation patterns on crop yields.”

2. Search Strategy

The search strategy describes how the literature was identified. This includes the databases and search engines used, search terms and keywords, and any inclusion or exclusion criteria.

Example: “The literature search was conducted using databases such as PubMed, Google Scholar, and JSTOR. Keywords included ‘climate change,’ ‘agriculture,’ ‘crop yields,’ and ‘precipitation patterns.’ Studies published between 2000 and 2023 were included.”

3. Theoretical Framework

The theoretical framework presents the theories and models relevant to the research topic. This section provides a foundation for understanding the studies reviewed.

Example: “This review utilizes the Sustainable Livelihoods Framework to analyze the impact of climate change on agricultural communities, focusing on how environmental changes affect economic stability and food security.”

4. Review of Literature

The core of the literature review, this section summarizes and synthesizes the findings of the selected studies. It is often organized thematically, chronologically, or methodologically.

Example: “Studies from the early 2000s focused on temperature changes, while recent research has shifted to examining precipitation patterns. Common findings include a general decline in crop yields, with significant regional variations.”

5. Critical Analysis

A critical analysis evaluates the strengths and weaknesses of the existing research. This involves assessing the methodology, data, and conclusions of the studies reviewed.

Example: “Many studies used longitudinal data to track changes over time, but few incorporated socioeconomic factors. Additionally, the reliance on regional data limits the generalizability of some findings.”

6. Discussion and Synthesis

The discussion and synthesis section integrates the findings from the literature review, highlighting common themes, trends, and gaps. It connects the reviewed studies to the current research question.

Example: “The literature consistently shows that rising temperatures negatively affect crop yields. However, there is a gap in understanding the role of adaptive farming practices, suggesting a need for further research in this area.”

7. Conclusion

The conclusion summarizes the main findings of the literature review. It reiterates the importance of the research topic and outlines the implications for future research.

Example: “In summary, climate change poses a significant threat to agricultural productivity. Future research should focus on adaptive strategies to mitigate these effects and ensure food security.”

8. References

The references section lists all the sources cited in the literature review. It should follow a specific citation style, such as APA, MLA, or Chicago.

• Smith, J. (2021). Climate Change and Crop Yields . Journal of Environmental Science, 12(3), 45-60.
• Brown, A., & Jones, B. (2019). Precipitation Patterns and Agriculture . Climate Research, 8(2), 34-48.

9. Appendices (if applicable)

Appendices may include supplementary material that is relevant to the literature review but would disrupt the flow of the main text. This could include tables, charts, or detailed methodological information.

Example: “Appendix A includes a table of regional crop yield changes from 2000 to 2020. Appendix B provides a detailed description of the data collection methods used in the reviewed studies.”

How to Write a Literature Review

Writing a literature review involves several steps to ensure that you provide a comprehensive, critical, and coherent summary of existing research on a specific topic. Here is a step-by-step guide to help you write an effective literature review:

1. Define Your Topic and Scope

• Identify your research question or thesis.
• Decide on the scope (broad topic or specific aspect, time frame, types of studies).

2. Conduct a Comprehensive Literature Search

• Identify key sources (use academic databases like PubMed, Google Scholar, JSTOR).
• Use relevant keywords to search for literature.
• Select relevant studies by reviewing abstracts.

3. Organize the Literature

• Group studies by themes (methodology, findings, theoretical perspective).
• Create an outline to structure your review.

4. Summarize and Synthesize the Literature

• Summarize key findings for each study.
• Synthesize information by comparing and contrasting studies.

5. Write the Literature Review

• Introduce the topic.
• Explain the purpose of the review.
• Outline the scope.
• Discuss literature thematically or chronologically.
• Present summaries and syntheses.
• Highlight patterns, contradictions, and gaps.
• Evaluate methodologies and findings.
• Discuss strengths and weaknesses of studies.
• Summarize main findings.
• Reiterate the importance of the topic.

6. Cite Your Sources

• Use a consistent citation style (APA, MLA, Chicago).

7. Review and Revise

• Proofread for grammatical errors and clarity.
• Revise for coherence and logical flow.

How do I start a literature review?

Begin by defining your research question and scope, then conduct a comprehensive search for relevant literature using academic databases.

What is the purpose of a theoretical framework?

It provides a foundation for understanding the literature and guides the analysis of existing studies.

How should I organize the literature review?

Organize it thematically, chronologically, or methodologically, depending on what best suits your research question.

How do I choose which studies to include?

Use inclusion and exclusion criteria based on relevance, publication date, and quality of the studies.

What is the difference between a thematic and chronological organization?

Thematic organization groups studies by topics or themes, while chronological organization arranges them by the date of publication.

How do I critically analyze the literature?

Evaluate the strengths and weaknesses of each study, assess methodologies, and discuss biases or gaps.

What should be included in the introduction?

Provide background information, state the purpose of the review, and outline its scope.

How can I synthesize findings from different studies?

Integrate the results to highlight common themes, trends, and gaps, providing a cohesive narrative.

Why are references important in a literature review?

References provide evidence for your review, ensure academic integrity, and allow readers to locate the original sources.

What role do appendices play in a literature review?

Appendices include supplementary material like tables or detailed methodologies that support the review but are too extensive for the main text.

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How to Prepare a Research Proposal and Literature Review

All HDR candidates are required to prepare a research proposal and literature review for their first Research Progress Review. If you are a PhD candidate, this will be your Confirmation Review. 

Your research proposal and literature review should be a comprehensive outline of your research topic and show how you will make an original contribution to knowledge in your field. Your Review panel will use your research proposal and literature review to assess the viability of your research project, and to provide you with valuable feedback on your topic, methodology, research design, timeline and milestones. 

UNSW Academic Skills provides a detailed description of how to develop and structure your research proposal. 

Your Faculty and/or School may have particular requirements, and you should contact your Postgraduate Coordinator or your supervisor if you’re unsure of what is required.  

Additional Resources

All disciplinary areas A guide for writing thesis proposals - UNSW Academic Skills Confirmation – not as big a deal as you think it is? - the Thesis Whisperer

Humanities and Social Sciences Essential ingredients of a good research proposal for undergraduate and postgraduate students in the social sciences – Raymond Talinbe Abdulai and Anthony Owusu-Ansah, SAGE Open, Jul-Sep 2014  Template for writing your PhD Confirmation document in Sociology and Anthropology - S A Hamed Hosseini

Science, Technology, Engineering and Medicine How to prepare a research proposal – Asya Al-Riyami, Oman Medical Journal Writing a scientific research proposal – author unknown

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• Volume 24, Issue 2
• Five tips for developing useful literature summary tables for writing review articles
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• http://orcid.org/0000-0003-0157-5319 Ahtisham Younas 1 , 2 ,
• http://orcid.org/0000-0002-7839-8130 Parveen Ali 3 , 4
• 1 Memorial University of Newfoundland , St John's , Newfoundland , Canada
• 2 Swat College of Nursing , Pakistan
• 3 School of Nursing and Midwifery , University of Sheffield , Sheffield , South Yorkshire , UK
• 4 Sheffield University Interpersonal Violence Research Group , Sheffield University , Sheffield , UK
• Correspondence to Ahtisham Younas, Memorial University of Newfoundland, St John's, NL A1C 5C4, Canada; ay6133{at}mun.ca

https://doi.org/10.1136/ebnurs-2021-103417

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Introduction

Literature reviews offer a critical synthesis of empirical and theoretical literature to assess the strength of evidence, develop guidelines for practice and policymaking, and identify areas for future research. 1 It is often essential and usually the first task in any research endeavour, particularly in masters or doctoral level education. For effective data extraction and rigorous synthesis in reviews, the use of literature summary tables is of utmost importance. A literature summary table provides a synopsis of an included article. It succinctly presents its purpose, methods, findings and other relevant information pertinent to the review. The aim of developing these literature summary tables is to provide the reader with the information at one glance. Since there are multiple types of reviews (eg, systematic, integrative, scoping, critical and mixed methods) with distinct purposes and techniques, 2 there could be various approaches for developing literature summary tables making it a complex task specialty for the novice researchers or reviewers. Here, we offer five tips for authors of the review articles, relevant to all types of reviews, for creating useful and relevant literature summary tables. We also provide examples from our published reviews to illustrate how useful literature summary tables can be developed and what sort of information should be provided.

Tip 1: provide detailed information about frameworks and methods

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Tabular literature summaries from a scoping review. Source: Rasheed et al . 3

The provision of information about conceptual and theoretical frameworks and methods is useful for several reasons. First, in quantitative (reviews synthesising the results of quantitative studies) and mixed reviews (reviews synthesising the results of both qualitative and quantitative studies to address a mixed review question), it allows the readers to assess the congruence of the core findings and methods with the adapted framework and tested assumptions. In qualitative reviews (reviews synthesising results of qualitative studies), this information is beneficial for readers to recognise the underlying philosophical and paradigmatic stance of the authors of the included articles. For example, imagine the authors of an article, included in a review, used phenomenological inquiry for their research. In that case, the review authors and the readers of the review need to know what kind of (transcendental or hermeneutic) philosophical stance guided the inquiry. Review authors should, therefore, include the philosophical stance in their literature summary for the particular article. Second, information about frameworks and methods enables review authors and readers to judge the quality of the research, which allows for discerning the strengths and limitations of the article. For example, if authors of an included article intended to develop a new scale and test its psychometric properties. To achieve this aim, they used a convenience sample of 150 participants and performed exploratory (EFA) and confirmatory factor analysis (CFA) on the same sample. Such an approach would indicate a flawed methodology because EFA and CFA should not be conducted on the same sample. The review authors must include this information in their summary table. Omitting this information from a summary could lead to the inclusion of a flawed article in the review, thereby jeopardising the review’s rigour.

Tip 2: include strengths and limitations for each article

Critical appraisal of individual articles included in a review is crucial for increasing the rigour of the review. Despite using various templates for critical appraisal, authors often do not provide detailed information about each reviewed article’s strengths and limitations. Merely noting the quality score based on standardised critical appraisal templates is not adequate because the readers should be able to identify the reasons for assigning a weak or moderate rating. Many recent critical appraisal checklists (eg, Mixed Methods Appraisal Tool) discourage review authors from assigning a quality score and recommend noting the main strengths and limitations of included studies. It is also vital that methodological and conceptual limitations and strengths of the articles included in the review are provided because not all review articles include empirical research papers. Rather some review synthesises the theoretical aspects of articles. Providing information about conceptual limitations is also important for readers to judge the quality of foundations of the research. For example, if you included a mixed-methods study in the review, reporting the methodological and conceptual limitations about ‘integration’ is critical for evaluating the study’s strength. Suppose the authors only collected qualitative and quantitative data and did not state the intent and timing of integration. In that case, the strength of the study is weak. Integration only occurred at the levels of data collection. However, integration may not have occurred at the analysis, interpretation and reporting levels.

Tip 3: write conceptual contribution of each reviewed article

While reading and evaluating review papers, we have observed that many review authors only provide core results of the article included in a review and do not explain the conceptual contribution offered by the included article. We refer to conceptual contribution as a description of how the article’s key results contribute towards the development of potential codes, themes or subthemes, or emerging patterns that are reported as the review findings. For example, the authors of a review article noted that one of the research articles included in their review demonstrated the usefulness of case studies and reflective logs as strategies for fostering compassion in nursing students. The conceptual contribution of this research article could be that experiential learning is one way to teach compassion to nursing students, as supported by case studies and reflective logs. This conceptual contribution of the article should be mentioned in the literature summary table. Delineating each reviewed article’s conceptual contribution is particularly beneficial in qualitative reviews, mixed-methods reviews, and critical reviews that often focus on developing models and describing or explaining various phenomena. Figure 2 offers an example of a literature summary table. 4

Tabular literature summaries from a critical review. Source: Younas and Maddigan. 4

Tip 4: compose potential themes from each article during summary writing

While developing literature summary tables, many authors use themes or subthemes reported in the given articles as the key results of their own review. Such an approach prevents the review authors from understanding the article’s conceptual contribution, developing rigorous synthesis and drawing reasonable interpretations of results from an individual article. Ultimately, it affects the generation of novel review findings. For example, one of the articles about women’s healthcare-seeking behaviours in developing countries reported a theme ‘social-cultural determinants of health as precursors of delays’. Instead of using this theme as one of the review findings, the reviewers should read and interpret beyond the given description in an article, compare and contrast themes, findings from one article with findings and themes from another article to find similarities and differences and to understand and explain bigger picture for their readers. Therefore, while developing literature summary tables, think twice before using the predeveloped themes. Including your themes in the summary tables (see figure 1 ) demonstrates to the readers that a robust method of data extraction and synthesis has been followed.

Tip 5: create your personalised template for literature summaries

Often templates are available for data extraction and development of literature summary tables. The available templates may be in the form of a table, chart or a structured framework that extracts some essential information about every article. The commonly used information may include authors, purpose, methods, key results and quality scores. While extracting all relevant information is important, such templates should be tailored to meet the needs of the individuals’ review. For example, for a review about the effectiveness of healthcare interventions, a literature summary table must include information about the intervention, its type, content timing, duration, setting, effectiveness, negative consequences, and receivers and implementers’ experiences of its usage. Similarly, literature summary tables for articles included in a meta-synthesis must include information about the participants’ characteristics, research context and conceptual contribution of each reviewed article so as to help the reader make an informed decision about the usefulness or lack of usefulness of the individual article in the review and the whole review.

In conclusion, narrative or systematic reviews are almost always conducted as a part of any educational project (thesis or dissertation) or academic or clinical research. Literature reviews are the foundation of research on a given topic. Robust and high-quality reviews play an instrumental role in guiding research, practice and policymaking. However, the quality of reviews is also contingent on rigorous data extraction and synthesis, which require developing literature summaries. We have outlined five tips that could enhance the quality of the data extraction and synthesis process by developing useful literature summaries.

• Aromataris E ,
• Rasheed SP ,

Twitter @Ahtisham04, @parveenazamali

Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

Competing interests None declared.

Patient consent for publication Not required.

Provenance and peer review Not commissioned; externally peer reviewed.

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How to write a literature review introduction (+ examples)

The introduction to a literature review serves as your reader’s guide through your academic work and thought process. Explore the significance of literature review introductions in review papers, academic papers, essays, theses, and dissertations. We delve into the purpose and necessity of these introductions, explore the essential components of literature review introductions, and provide step-by-step guidance on how to craft your own, along with examples.

Why you need an introduction for a literature review

In academic writing , the introduction for a literature review is an indispensable component. Effective academic writing requires proper paragraph structuring to guide your reader through your argumentation. This includes providing an introduction to your literature review.

It is imperative to remember that you should never start sharing your findings abruptly. Even if there isn’t a dedicated introduction section .

When you need an introduction for a literature review

There are three main scenarios in which you need an introduction for a literature review:

What to include in a literature review introduction

It is crucial to customize the content and depth of your literature review introduction according to the specific format of your academic work.

Academic literature review paper

The introduction of an academic literature review paper, which does not rely on empirical data, often necessitates a more extensive introduction than the brief literature review introductions typically found in empirical papers. It should encompass:

Regular literature review section in an academic article or essay

In a standard 8000-word journal article, the literature review section typically spans between 750 and 1250 words. The first few sentences or the first paragraph within this section often serve as an introduction. It should encompass:

Introduction to a literature review chapter in thesis or dissertation

Some students choose to incorporate a brief introductory section at the beginning of each chapter, including the literature review chapter. Alternatively, others opt to seamlessly integrate the introduction into the initial sentences of the literature review itself. Both approaches are acceptable, provided that you incorporate the following elements:

Examples of literature review introductions

Example 1: an effective introduction for an academic literature review paper.

To begin, let’s delve into the introduction of an academic literature review paper. We will examine the paper “How does culture influence innovation? A systematic literature review”, which was published in 2018 in the journal Management Decision.

Example 2: An effective introduction to a literature review section in an academic paper

The second example represents a typical academic paper, encompassing not only a literature review section but also empirical data, a case study, and other elements. We will closely examine the introduction to the literature review section in the paper “The environmentalism of the subalterns: a case study of environmental activism in Eastern Kurdistan/Rojhelat”, which was published in 2021 in the journal Local Environment.

Thus, the author successfully introduces the literature review, from which point onward it dives into the main concept (‘subalternity’) of the research, and reviews the literature on socio-economic justice and environmental degradation.

Examples 3-5: Effective introductions to literature review chapters

Numerous universities offer online repositories where you can access theses and dissertations from previous years, serving as valuable sources of reference. Many of these repositories, however, may require you to log in through your university account. Nevertheless, a few open-access repositories are accessible to anyone, such as the one by the University of Manchester . It’s important to note though that copyright restrictions apply to these resources, just as they would with published papers.

Master’s thesis literature review introduction

Phd thesis literature review chapter introduction.

The second example is Deep Learning on Semi-Structured Data and its Applications to Video-Game AI, Woof, W. (Author). 31 Dec 2020, a PhD thesis completed at the University of Manchester . In Chapter 2, the author offers a comprehensive introduction to the topic in four paragraphs, with the final paragraph serving as an overview of the chapter’s structure:

PhD thesis literature review introduction

The last example is the doctoral thesis Metacognitive strategies and beliefs: Child correlates and early experiences Chan, K. Y. M. (Author). 31 Dec 2020 . The author clearly conducted a systematic literature review, commencing the review section with a discussion of the methodology and approach employed in locating and analyzing the selected records.

Steps to write your own literature review introduction

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Ten Simple Rules for Writing a Literature Review

Marco pautasso.

1 Centre for Functional and Evolutionary Ecology (CEFE), CNRS, Montpellier, France

2 Centre for Biodiversity Synthesis and Analysis (CESAB), FRB, Aix-en-Provence, France

Literature reviews are in great demand in most scientific fields. Their need stems from the ever-increasing output of scientific publications [1] . For example, compared to 1991, in 2008 three, eight, and forty times more papers were indexed in Web of Science on malaria, obesity, and biodiversity, respectively [2] . Given such mountains of papers, scientists cannot be expected to examine in detail every single new paper relevant to their interests [3] . Thus, it is both advantageous and necessary to rely on regular summaries of the recent literature. Although recognition for scientists mainly comes from primary research, timely literature reviews can lead to new synthetic insights and are often widely read [4] . For such summaries to be useful, however, they need to be compiled in a professional way [5] .

When starting from scratch, reviewing the literature can require a titanic amount of work. That is why researchers who have spent their career working on a certain research issue are in a perfect position to review that literature. Some graduate schools are now offering courses in reviewing the literature, given that most research students start their project by producing an overview of what has already been done on their research issue [6] . However, it is likely that most scientists have not thought in detail about how to approach and carry out a literature review.

Reviewing the literature requires the ability to juggle multiple tasks, from finding and evaluating relevant material to synthesising information from various sources, from critical thinking to paraphrasing, evaluating, and citation skills [7] . In this contribution, I share ten simple rules I learned working on about 25 literature reviews as a PhD and postdoctoral student. Ideas and insights also come from discussions with coauthors and colleagues, as well as feedback from reviewers and editors.

Rule 1: Define a Topic and Audience

How to choose which topic to review? There are so many issues in contemporary science that you could spend a lifetime of attending conferences and reading the literature just pondering what to review. On the one hand, if you take several years to choose, several other people may have had the same idea in the meantime. On the other hand, only a well-considered topic is likely to lead to a brilliant literature review [8] . The topic must at least be:

• interesting to you (ideally, you should have come across a series of recent papers related to your line of work that call for a critical summary),
• an important aspect of the field (so that many readers will be interested in the review and there will be enough material to write it), and
• a well-defined issue (otherwise you could potentially include thousands of publications, which would make the review unhelpful).

Ideas for potential reviews may come from papers providing lists of key research questions to be answered [9] , but also from serendipitous moments during desultory reading and discussions. In addition to choosing your topic, you should also select a target audience. In many cases, the topic (e.g., web services in computational biology) will automatically define an audience (e.g., computational biologists), but that same topic may also be of interest to neighbouring fields (e.g., computer science, biology, etc.).

Rule 2: Search and Re-search the Literature

After having chosen your topic and audience, start by checking the literature and downloading relevant papers. Five pieces of advice here:

• keep track of the search items you use (so that your search can be replicated [10] ),
• keep a list of papers whose pdfs you cannot access immediately (so as to retrieve them later with alternative strategies),
• use a paper management system (e.g., Mendeley, Papers, Qiqqa, Sente),
• define early in the process some criteria for exclusion of irrelevant papers (these criteria can then be described in the review to help define its scope), and
• do not just look for research papers in the area you wish to review, but also seek previous reviews.

The chances are high that someone will already have published a literature review ( Figure 1 ), if not exactly on the issue you are planning to tackle, at least on a related topic. If there are already a few or several reviews of the literature on your issue, my advice is not to give up, but to carry on with your own literature review,

The bottom-right situation (many literature reviews but few research papers) is not just a theoretical situation; it applies, for example, to the study of the impacts of climate change on plant diseases, where there appear to be more literature reviews than research studies [33] .

• discussing in your review the approaches, limitations, and conclusions of past reviews,
• trying to find a new angle that has not been covered adequately in the previous reviews, and
• incorporating new material that has inevitably accumulated since their appearance.

When searching the literature for pertinent papers and reviews, the usual rules apply:

• be thorough,
• use different keywords and database sources (e.g., DBLP, Google Scholar, ISI Proceedings, JSTOR Search, Medline, Scopus, Web of Science), and
• look at who has cited past relevant papers and book chapters.

Rule 3: Take Notes While Reading

If you read the papers first, and only afterwards start writing the review, you will need a very good memory to remember who wrote what, and what your impressions and associations were while reading each single paper. My advice is, while reading, to start writing down interesting pieces of information, insights about how to organize the review, and thoughts on what to write. This way, by the time you have read the literature you selected, you will already have a rough draft of the review.

Of course, this draft will still need much rewriting, restructuring, and rethinking to obtain a text with a coherent argument [11] , but you will have avoided the danger posed by staring at a blank document. Be careful when taking notes to use quotation marks if you are provisionally copying verbatim from the literature. It is advisable then to reformulate such quotes with your own words in the final draft. It is important to be careful in noting the references already at this stage, so as to avoid misattributions. Using referencing software from the very beginning of your endeavour will save you time.

Rule 4: Choose the Type of Review You Wish to Write

After having taken notes while reading the literature, you will have a rough idea of the amount of material available for the review. This is probably a good time to decide whether to go for a mini- or a full review. Some journals are now favouring the publication of rather short reviews focusing on the last few years, with a limit on the number of words and citations. A mini-review is not necessarily a minor review: it may well attract more attention from busy readers, although it will inevitably simplify some issues and leave out some relevant material due to space limitations. A full review will have the advantage of more freedom to cover in detail the complexities of a particular scientific development, but may then be left in the pile of the very important papers “to be read” by readers with little time to spare for major monographs.

There is probably a continuum between mini- and full reviews. The same point applies to the dichotomy of descriptive vs. integrative reviews. While descriptive reviews focus on the methodology, findings, and interpretation of each reviewed study, integrative reviews attempt to find common ideas and concepts from the reviewed material [12] . A similar distinction exists between narrative and systematic reviews: while narrative reviews are qualitative, systematic reviews attempt to test a hypothesis based on the published evidence, which is gathered using a predefined protocol to reduce bias [13] , [14] . When systematic reviews analyse quantitative results in a quantitative way, they become meta-analyses. The choice between different review types will have to be made on a case-by-case basis, depending not just on the nature of the material found and the preferences of the target journal(s), but also on the time available to write the review and the number of coauthors [15] .

Rule 5: Keep the Review Focused, but Make It of Broad Interest

Whether your plan is to write a mini- or a full review, it is good advice to keep it focused 16 , 17 . Including material just for the sake of it can easily lead to reviews that are trying to do too many things at once. The need to keep a review focused can be problematic for interdisciplinary reviews, where the aim is to bridge the gap between fields [18] . If you are writing a review on, for example, how epidemiological approaches are used in modelling the spread of ideas, you may be inclined to include material from both parent fields, epidemiology and the study of cultural diffusion. This may be necessary to some extent, but in this case a focused review would only deal in detail with those studies at the interface between epidemiology and the spread of ideas.

While focus is an important feature of a successful review, this requirement has to be balanced with the need to make the review relevant to a broad audience. This square may be circled by discussing the wider implications of the reviewed topic for other disciplines.

Rule 6: Be Critical and Consistent

Reviewing the literature is not stamp collecting. A good review does not just summarize the literature, but discusses it critically, identifies methodological problems, and points out research gaps [19] . After having read a review of the literature, a reader should have a rough idea of:

• the major achievements in the reviewed field,
• the main areas of debate, and
• the outstanding research questions.

It is challenging to achieve a successful review on all these fronts. A solution can be to involve a set of complementary coauthors: some people are excellent at mapping what has been achieved, some others are very good at identifying dark clouds on the horizon, and some have instead a knack at predicting where solutions are going to come from. If your journal club has exactly this sort of team, then you should definitely write a review of the literature! In addition to critical thinking, a literature review needs consistency, for example in the choice of passive vs. active voice and present vs. past tense.

Rule 7: Find a Logical Structure

Like a well-baked cake, a good review has a number of telling features: it is worth the reader's time, timely, systematic, well written, focused, and critical. It also needs a good structure. With reviews, the usual subdivision of research papers into introduction, methods, results, and discussion does not work or is rarely used. However, a general introduction of the context and, toward the end, a recapitulation of the main points covered and take-home messages make sense also in the case of reviews. For systematic reviews, there is a trend towards including information about how the literature was searched (database, keywords, time limits) [20] .

How can you organize the flow of the main body of the review so that the reader will be drawn into and guided through it? It is generally helpful to draw a conceptual scheme of the review, e.g., with mind-mapping techniques. Such diagrams can help recognize a logical way to order and link the various sections of a review [21] . This is the case not just at the writing stage, but also for readers if the diagram is included in the review as a figure. A careful selection of diagrams and figures relevant to the reviewed topic can be very helpful to structure the text too [22] .

Rule 8: Make Use of Feedback

Reviews of the literature are normally peer-reviewed in the same way as research papers, and rightly so [23] . As a rule, incorporating feedback from reviewers greatly helps improve a review draft. Having read the review with a fresh mind, reviewers may spot inaccuracies, inconsistencies, and ambiguities that had not been noticed by the writers due to rereading the typescript too many times. It is however advisable to reread the draft one more time before submission, as a last-minute correction of typos, leaps, and muddled sentences may enable the reviewers to focus on providing advice on the content rather than the form.

Feedback is vital to writing a good review, and should be sought from a variety of colleagues, so as to obtain a diversity of views on the draft. This may lead in some cases to conflicting views on the merits of the paper, and on how to improve it, but such a situation is better than the absence of feedback. A diversity of feedback perspectives on a literature review can help identify where the consensus view stands in the landscape of the current scientific understanding of an issue [24] .

Rule 9: Include Your Own Relevant Research, but Be Objective

In many cases, reviewers of the literature will have published studies relevant to the review they are writing. This could create a conflict of interest: how can reviewers report objectively on their own work [25] ? Some scientists may be overly enthusiastic about what they have published, and thus risk giving too much importance to their own findings in the review. However, bias could also occur in the other direction: some scientists may be unduly dismissive of their own achievements, so that they will tend to downplay their contribution (if any) to a field when reviewing it.

In general, a review of the literature should neither be a public relations brochure nor an exercise in competitive self-denial. If a reviewer is up to the job of producing a well-organized and methodical review, which flows well and provides a service to the readership, then it should be possible to be objective in reviewing one's own relevant findings. In reviews written by multiple authors, this may be achieved by assigning the review of the results of a coauthor to different coauthors.

Rule 10: Be Up-to-Date, but Do Not Forget Older Studies

Given the progressive acceleration in the publication of scientific papers, today's reviews of the literature need awareness not just of the overall direction and achievements of a field of inquiry, but also of the latest studies, so as not to become out-of-date before they have been published. Ideally, a literature review should not identify as a major research gap an issue that has just been addressed in a series of papers in press (the same applies, of course, to older, overlooked studies (“sleeping beauties” [26] )). This implies that literature reviewers would do well to keep an eye on electronic lists of papers in press, given that it can take months before these appear in scientific databases. Some reviews declare that they have scanned the literature up to a certain point in time, but given that peer review can be a rather lengthy process, a full search for newly appeared literature at the revision stage may be worthwhile. Assessing the contribution of papers that have just appeared is particularly challenging, because there is little perspective with which to gauge their significance and impact on further research and society.

Inevitably, new papers on the reviewed topic (including independently written literature reviews) will appear from all quarters after the review has been published, so that there may soon be the need for an updated review. But this is the nature of science [27] – [32] . I wish everybody good luck with writing a review of the literature.

Acknowledgments

Many thanks to M. Barbosa, K. Dehnen-Schmutz, T. Döring, D. Fontaneto, M. Garbelotto, O. Holdenrieder, M. Jeger, D. Lonsdale, A. MacLeod, P. Mills, M. Moslonka-Lefebvre, G. Stancanelli, P. Weisberg, and X. Xu for insights and discussions, and to P. Bourne, T. Matoni, and D. Smith for helpful comments on a previous draft.

Funding Statement

This work was funded by the French Foundation for Research on Biodiversity (FRB) through its Centre for Synthesis and Analysis of Biodiversity data (CESAB), as part of the NETSEED research project. The funders had no role in the preparation of the manuscript.

How To Structure Your Literature Review

3 options to help structure your chapter.

By: Amy Rommelspacher (PhD) | Reviewer: Dr Eunice Rautenbach | November 2020 (Updated May 2023)

Writing the literature review chapter can seem pretty daunting when you’re piecing together your dissertation or thesis. As  we’ve discussed before , a good literature review needs to achieve a few very important objectives – it should:

• Demonstrate your knowledge of the research topic
• Identify the gaps in the literature and show how your research links to these
• Provide the foundation for your conceptual framework (if you have one)
• Inform your own  methodology and research design

To achieve this, your literature review needs a well-thought-out structure . Get the structure of your literature review chapter wrong and you’ll struggle to achieve these objectives. Don’t worry though – in this post, we’ll look at how to structure your literature review for maximum impact (and marks!).

But wait – is this the right time?

Deciding on the structure of your literature review should come towards the end of the literature review process – after you have collected and digested the literature, but before you start writing the chapter. 

In other words, you need to first develop a rich understanding of the literature before you even attempt to map out a structure. There’s no use trying to develop a structure before you’ve fully wrapped your head around the existing research.

Equally importantly, you need to have a structure in place before you start writing , or your literature review will most likely end up a rambling, disjointed mess. 

Importantly, don’t feel that once you’ve defined a structure you can’t iterate on it. It’s perfectly natural to adjust as you engage in the writing process. As we’ve discussed before , writing is a way of developing your thinking, so it’s quite common for your thinking to change – and therefore, for your chapter structure to change – as you write. 

Need a helping hand?

Like any other chapter in your thesis or dissertation, your literature review needs to have a clear, logical structure. At a minimum, it should have three essential components – an  introduction , a  body   and a  conclusion . 

Let’s take a closer look at each of these.

1: The Introduction Section

Just like any good introduction, the introduction section of your literature review should introduce the purpose and layout (organisation) of the chapter. In other words, your introduction needs to give the reader a taste of what’s to come, and how you’re going to lay that out. Essentially, you should provide the reader with a high-level roadmap of your chapter to give them a taste of the journey that lies ahead.

Here’s an example of the layout visualised in a literature review introduction:

Your introduction should also outline your topic (including any tricky terminology or jargon) and provide an explanation of the scope of your literature review – in other words, what you  will   and  won’t   be covering (the delimitations ). This helps ringfence your review and achieve a clear focus . The clearer and narrower your focus, the deeper you can dive into the topic (which is typically where the magic lies). 

Depending on the nature of your project, you could also present your stance or point of view at this stage. In other words, after grappling with the literature you’ll have an opinion about what the trends and concerns are in the field as well as what’s lacking. The introduction section can then present these ideas so that it is clear to examiners that you’re aware of how your research connects with existing knowledge .

2: The Body Section

The body of your literature review is the centre of your work. This is where you’ll present, analyse, evaluate and synthesise the existing research. In other words, this is where you’re going to earn (or lose) the most marks. Therefore, it’s important to carefully think about how you will organise your discussion to present it in a clear way. 

The body of your literature review should do just as the description of this chapter suggests. It should “review” the literature – in other words, identify, analyse, and synthesise it. So, when thinking about structuring your literature review, you need to think about which structural approach will provide the best “review” for your specific type of research and objectives (we’ll get to this shortly).

There are (broadly speaking)  three options  for organising your literature review.

Option 1: Chronological (according to date)

Organising the literature chronologically is one of the simplest ways to structure your literature review. You start with what was published first and work your way through the literature until you reach the work published most recently. Pretty straightforward.

The benefit of this option is that it makes it easy to discuss the developments and debates in the field as they emerged over time. Organising your literature chronologically also allows you to highlight how specific articles or pieces of work might have changed the course of the field – in other words, which research has had the most impact . Therefore, this approach is very useful when your research is aimed at understanding how the topic has unfolded over time and is often used by scholars in the field of history. That said, this approach can be utilised by anyone that wants to explore change over time .

For example , if a student of politics is investigating how the understanding of democracy has evolved over time, they could use the chronological approach to provide a narrative that demonstrates how this understanding has changed through the ages.

Here are some questions you can ask yourself to help you structure your literature review chronologically.

• What is the earliest literature published relating to this topic?
• How has the field changed over time? Why?
• What are the most recent discoveries/theories?

In some ways, chronology plays a part whichever way you decide to structure your literature review, because you will always, to a certain extent, be analysing how the literature has developed. However, with the chronological approach, the emphasis is very firmly on how the discussion has evolved over time , as opposed to how all the literature links together (which we’ll discuss next ).

Option 2: Thematic (grouped by theme)

The thematic approach to structuring a literature review means organising your literature by theme or category – for example, by independent variables (i.e. factors that have an impact on a specific outcome).

As you’ve been collecting and synthesising literature , you’ll likely have started seeing some themes or patterns emerging. You can then use these themes or patterns as a structure for your body discussion. The thematic approach is the most common approach and is useful for structuring literature reviews in most fields.

For example, if you were researching which factors contributed towards people trusting an organisation, you might find themes such as consumers’ perceptions of an organisation’s competence, benevolence and integrity. Structuring your literature review thematically would mean structuring your literature review’s body section to discuss each of these themes, one section at a time.

Here are some questions to ask yourself when structuring your literature review by themes:

• Are there any patterns that have come to light in the literature?
• What are the central themes and categories used by the researchers?
• Do I have enough evidence of these themes?

PS – you can see an example of a thematically structured literature review in our literature review sample walkthrough video here.

Option 3: Methodological

The methodological option is a way of structuring your literature review by the research methodologies used . In other words, organising your discussion based on the angle from which each piece of research was approached – for example, qualitative , quantitative or mixed  methodologies.

Structuring your literature review by methodology can be useful if you are drawing research from a variety of disciplines and are critiquing different methodologies. The point of this approach is to question  how  existing research has been conducted, as opposed to  what  the conclusions and/or findings the research were.

For example, a sociologist might centre their research around critiquing specific fieldwork practices. Their literature review will then be a summary of the fieldwork methodologies used by different studies.

Here are some questions you can ask yourself when structuring your literature review according to methodology:

• Which methodologies have been utilised in this field?
• Which methodology is the most popular (and why)?
• What are the strengths and weaknesses of the various methodologies?
• How can the existing methodologies inform my own methodology?

3: The Conclusion Section

Once you’ve completed the body section of your literature review using one of the structural approaches we discussed above, you’ll need to “wrap up” your literature review and pull all the pieces together to set the direction for the rest of your dissertation or thesis.

The conclusion is where you’ll present the key findings of your literature review. In this section, you should emphasise the research that is especially important to your research questions and highlight the gaps that exist in the literature. Based on this, you need to make it clear what you will add to the literature – in other words, justify your own research by showing how it will help fill one or more of the gaps you just identified.

Last but not least, if it’s your intention to develop a conceptual framework for your dissertation or thesis, the conclusion section is a good place to present this.

Example: Thematically Structured Review

In the video below, we unpack a literature review chapter so that you can see an example of a thematically structure review in practice.

Let’s Recap

In this article, we’ve  discussed how to structure your literature review for maximum impact. Here’s a quick recap of what  you need to keep in mind when deciding on your literature review structure:

• Just like other chapters, your literature review needs a clear introduction , body and conclusion .
• The introduction section should provide an overview of what you will discuss in your literature review.
• The body section of your literature review can be organised by chronology , theme or methodology . The right structural approach depends on what you’re trying to achieve with your research.
• The conclusion section should draw together the key findings of your literature review and link them to your research questions.

If you’re ready to get started, be sure to download our free literature review template to fast-track your chapter outline.

Psst… there’s more!

This post is an extract from our bestselling short course, Literature Review Bootcamp . If you want to work smart, you don't want to miss this .

27 Comments

Great work. This is exactly what I was looking for and helps a lot together with your previous post on literature review. One last thing is missing: a link to a great literature chapter of an journal article (maybe with comments of the different sections in this review chapter). Do you know any great literature review chapters?

I agree with you Marin… A great piece

I agree with Marin. This would be quite helpful if you annotate a nicely structured literature from previously published research articles.

Awesome article for my research.

I thank you immensely for this wonderful guide

It is indeed thought and supportive work for the futurist researcher and students

Very educative and good time to get guide. Thank you

Great work, very insightful. Thank you.

Thanks for this wonderful presentation. My question is that do I put all the variables into a single conceptual framework or each hypothesis will have it own conceptual framework?

Thank you very much, very helpful

This is very educative and precise . Thank you very much for dropping this kind of write up .

Pheeww, so damn helpful, thank you for this informative piece.

I’m doing a research project topic ; stool analysis for parasitic worm (enteric) worm, how do I structure it, thanks.

comprehensive explanation. Help us by pasting the URL of some good “literature review” for better understanding.

great piece. thanks for the awesome explanation. it is really worth sharing. I have a little question, if anyone can help me out, which of the options in the body of literature can be best fit if you are writing an architectural thesis that deals with design?

I am doing a research on nanofluids how can l structure it?

Beautifully clear.nThank you!

Lucid! Thankyou!

Brilliant work, well understood, many thanks

I like how this was so clear with simple language 😊😊 thank you so much 😊 for these information 😊

Insightful. I was struggling to come up with a sensible literature review but this has been really helpful. Thank you!

You have given thought-provoking information about the review of the literature.

Thank you. It has made my own research better and to impart your work to students I teach

I learnt a lot from this teaching. It’s a great piece.

I am doing research on EFL teacher motivation for his/her job. How Can I structure it? Is there any detailed template, additional to this?

You are so cool! I do not think I’ve read through something like this before. So nice to find somebody with some genuine thoughts on this issue. Seriously.. thank you for starting this up. This site is one thing that is required on the internet, someone with a little originality!

I’m asked to do conceptual, theoretical and empirical literature, and i just don’t know how to structure it

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Importance of Literature Review in Research Proposals

Table of Contents

A literature review is an integral part of any research proposal. What should a sample literature review for research proposal contain? You’ll find answers to this question in this article.

But first, let’s understand the importance of a literature review in a research proposal.

What Is the Importance of Literature Review in a Research Proposal

A literature review helps to introduce the topic being addressed and provides a detailed overview of the existing knowledge on that subject. Also, it points out areas where there may be gaps in the current understanding or where more research is needed.

Furthermore, reading other authors’ works can provide insight into how they tackled a similar question or issue. It may even help the student refine their research question.

What Should a Good Sample Literature Review for Research Proposal Include?

A good sample literature review for research proposal should cover all essential elements. We explain these key elements below.

Include the Most Relevant Works

Relevant works are essential to your literature review. It is one of the most important things you must pay attention to. You can’t show that you’ve thoroughly researched the topic without including the most pertinent works.

Therefore, you must select the most relevant works according to their relevance to the question being addressed.

State How They Support Your Research

It’s crucial to clearly state how these works support your research. By introducing this body of work, you are providing the context which allows others to understand why you have chosen a particular method.

It is also a way of giving them an idea of the results you will achieve and the potential impact of your proposed study. It may also help to move new scientific research forward.

Choose up-to-Date Sources

To get the best out of a literature review, choose sources that are up-to-date and provide a variety of perspectives.

Your sources must be up-to-date to avoid instances where your thesis is based on outdated research. A literature review should include essential information from multiple sources, including articles, books, journals, websites, and databases.

How to Write Your Literature Review

Below are tips to help you write a good literature review.

Create an Outline

Don’t give in to the temptation to simply start writing right away. You may get confused. By creating an outline, you’ll be able to piece up every bit of information you’ve gathered logically. Without an outline, you may end up missing out on key details or presenting illogical arguments.

Draft Your Literature Review

With your outline, you can now draft your literature review. Remember that your first draft doesn’t have to be perfect. Trying to write an excellent literature review the first time isn’t always possible.

Don’t put too much pressure on yourself. Instead, focus on putting something down first. After your first draft, you may take time off to cool off. Come back to it after a day or two to perfect the rough edges.

Finally, you should proofread your final draft. Check to make sure your grammar and punctuation are on point. Don’t forget your citations as well. Make sure all sources are appropriately cited.

Final Thoughts

A literature review is an essential part of a research proposal. It allows you to survey and analyze existing information on a given topic from multiple sources , including articles, books, journals, websites, and databases. It helps to establish the relevancy and validity of your research proposal.

Abir Ghenaiet

Abir is a data analyst and researcher. Among her interests are artificial intelligence, machine learning, and natural language processing. As a humanitarian and educator, she actively supports women in tech and promotes diversity.

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• Open access
• Published: 10 July 2024

Analysis and mapping of harm reduction research in the context of injectable drug use: identifying research hotspots, gaps and future directions

• Waleed M. Sweileh   ORCID: orcid.org/0000-0002-9460-5144 1  

Harm Reduction Journal volume  21 , Article number:  131 ( 2024 ) Cite this article

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Metrics details

Harm reduction is a crucial approach in addressing the multifaceted challenges of injectable drug use. This paper presents an analysis and mapping of the existing literature on harm reduction research in the context of injectable drug use. By reviewing a comprehensive set of scholarly articles, this study identifies research hotspots, knowledge gaps, and future directions in the field. The findings provide valuable insights for researchers, policymakers, and practitioners to guide future research efforts and inform evidence-based harm reduction interventions.

Data for the study was obtained from the Scopus database, using keywords and phrases related to harm reduction and injectable drug use. Validation methods were employed to verify the accuracy and comprehensiveness of the search strategy. Data analysis involved identifying growth patterns, key contributors, mapping frequent terms, identifying research hotspots, and identifying emerging research directions.

A total of 971 articles were found, with a notable increase from 2015 to 2022. The International Journal of Drug Policy ( n  = 172, 17.7%) and the Harm Reduction Journal ( n  = 104, 10.7%) were the most prolific journals, and the United States ( n  = 558, 57.5%) had the highest number of publications. The Johns Hopkins University ( n  = 80, 8.5%) was the most prolific institution. Mapping of frequent author keywords revealed the main keywords, including harm reduction, HIV, hepatitis C, and opioid overdose. The highly cited articles cover a broad time span and focus on topics like naloxone distribution, HIV and hepatitis C transmission, while recent articles concentrate on emerging issues such as the impact of the COVID-19 pandemic, fentanyl-related concerns, stigma reduction, and needle and syringe programs. Both sets of articles share a common focus on harm reduction strategies, but recent publications highlight current challenges and developments in the field.

Conclusions

This study provides insights into research landscape on harm reduction in injectable drug use. Research is concentrated in high-income countries, emphasizing the need for more research in low- and middle-income countries. Recent publications focus on emerging challenges like COVID-19 and fentanyl. Research gaps highlight the need for studies in diverse populations, social determinants, program evaluation, and implementation strategies to enhance harm reduction interventions.

Substance use disorder (SUD) is a condition in which the consumption of one or more substances results in clinically significant impairment or distress. This disorder is marked by the recurrent use of alcohol and/or drugs, leading to serious health problems, disability, and an inability to fulfill major responsibilities at work, school, or home [ 1 , 2 ]. The excessive and repeated intake of these substances brings about detrimental physical, psychological, and social effects. SUD imposes a substantial global burden, affecting individuals, families, and communities by compromising health, social relationships, and economic stability [ 3 , 4 , 5 ]. Among the various substances abused, injectable drug use (IDU) poses the most severe health and overdose risks [ 6 ]. Injectable drugs, administered directly into the bloodstream via needle and syringe, include illicit substances like heroin and cocaine, as well as certain prescription medications such as opioids [ 7 ]. The prevalence of IDU within the broader spectrum of SUD varies across regions and populations. According to the World Drug Report 2020 by the United Nations Office on Drugs and Crime (UNODC), approximately 10.5 million people globally engage in drug injection [ 8 ].

Harm reduction and prevention strategies play a crucial role in addressing IDU and its associated harms [ 9 , 10 ]. One significant harm is the risk of overdose, which can be addressed through various strategies. For instance, distributing naloxone, an opioid overdose reversal medication, to individuals who use opioids can save lives [ 9 , 11 , 12 ]. Harm reduction also focuses on preventing the transmission of blood-borne diseases like HIV and hepatitis by providing clean needles and syringes through needle and syringe programs. These initiatives help reduce the spread of infections among people who inject drugs. Harm reduction initiatives and prevention strategies work to mitigate negative health consequences of IDU by promoting safer practices and reducing stigmatization. By providing individuals with accurate information and education about safer drug use practices, harm reduction programs help minimize the risks associated with IDU. Additionally, supporting individuals in their recovery journey through counseling, peer support, and access to treatment options can positively impact their lives and reduce the social and economic burdens of IDU [ 11 , 13 ]. Harm reduction and prevention efforts focus on ensuring individuals have access to evidence-based interventions, support services, and treatment options. This includes providing opioid agonist treatment, which involves substituting illicit opioids with prescribed medications such as methadone or buprenorphine [ 9 , 14 , 15 ]. Opioid agonist treatment helps individuals manage their substance use disorder, reduce cravings, and improve their overall well-being [ 12 , 13 , 16 ]. Harm reduction and prevention strategies have broader implications for public health and community safety. By preventing the spread of diseases like HIV and hepatitis, harm reduction initiatives contribute to the overall well-being of communities. Furthermore, these approaches can help reduce drug-related crime rates. By shifting the focus from punitive measures to public health-oriented strategies, such as outreach programs and harm reduction services, communities can create safer environments and reduce the negative impacts of drug-related criminal activities [ 17 ].

The research landscape refers to the overall state of scientific knowledge, studies, and research activities in a specific field or area of inquiry. It encompasses the existing literature, research gaps, methodologies, key findings, and emerging trends within the subject of interest [ 18 ]. The current study aims to identify current state of scientific literature, identifying gaps, and provide recommendations for future research priorities and directions to reduce harm in the context of IDU. A landscape research analysis on harm reduction of IDU is expected to provide a comprehensive overview of the existing literature, identify research hotspots, and highlight gaps and areas for further research. By analyzing the research landscape, policymakers and funders can gain insights into areas that require increased investment and support. This analysis helps ensure that resources are allocated efficiently to address priority research questions and areas of need. Research landscape analysis allows researchers and organizations to identify potential collaborators and foster interdisciplinary collaborations. By understanding the existing research networks and collaborations, stakeholders can work together to address complex challenges in harm reduction among individuals who inject drugs.

Data source

The primary data source for the current study was Scopus, a comprehensive bibliographic database that includes a wide range of scholarly publications across various disciplines ( www.scopus.com ).

Search strategy

A search was conducted using relevant keywords and phrases related to harm reduction and “IDU”. All retrieved articles must include specific terms in their titles to ensure relevance to IDU. These terms were: “opioid*” or “heroin” or “inject* drugs” or (“inject” and “stimulant*”) or “needle drug use” or (“inject” and “opioid”) or (“inject” and “heroin”) or (“inject” and “cocaine”) or (“inject” and “amphetamine”) or (inject* and drug*). This comprehensive set of search terms ensures that the articles retrieved were directly related to the study of opioid use, heroin use, injectable drugs, stimulant injection, and needle drug use. To ensure that these terms were used in the context of injections, the following keywords must be present in the title and/or abstract: inject* or needle* or intravenous or syringe*. Harm reduction is a broad concept and developing a comprehensive search strategy might be difficult. However, in the current study, maximum number of available keywords related to harm reduction, programs, interventions, policies, initiatives were included. To ensure that retrieved articles are relevant to harm reduction, they must include specific terms or phrases in their titles and/or abstracts. these terms are: “collaboration with community organizations” or “family and social network involvement” or “supportive housing” or “employment and vocational support” or “education and awareness” or “policy interventions” or “treatment and rehabilitation” or “media and advertising regulations” or “research and monitoring” or “prevent* blood borne infect*” or “harm reduction” or “harm minimization” or “risk reduction” or “damage reduction” or “health promotion” or “safer use” or “safety-focused approaches” or “minimizing adverse consequences” or “public health approach” or “health-centered interventions” or “prevention of harm” or “behavior-based interventions” or “reduction of negative outcomes” or “mitigation of risks” or “safety strategies” or “needle exchange program*” or “safer injection practice*” or “overdose prevention” or “safe substance use” or “substance use treatment alternatives” or “syringe access program*” or “safer drug use practice*” or “syringe exchange program” or “HIV transmission” or “virus transmission” or “condom use” or (“blood borne infect*” and prevent*) or “needle and syringe program*” or “harm reduction program*” or “needle distribution program*” or “opioid substitution therapy” or “medication-assisted treatment” or “opioid detoxification programs” or “education and awareness campaign*” or “substance abuse prevention campaign*” or “drug education programs” or “public awareness initiatives” or “information campaign*” or “safer sex practices” or “harm reduction in sexual behavior” or “safe sex education” or “condom use promotion” or “barrier method education” or “preventing sexually transmitted” or “harm reduction drug testing” or “naloxone distribution” or “naloxone access programs” or “overdose reversal medication distribution” or “narcan distribution” or “opioid overdose rescue kits” or “supervised consumption facilit*” or “medically supervised drug consumption site*” or “overdose prevention centers” or “supervised injection services” or “street outreach service*” or “mobile harm reduction program*” or “outreach services for people who use drugs” or “harm reduction outreach activities” or “peer support program*” or “peers in recovery programs” or “peer mentoring for substance abuse” or “support networks of individuals with lived experience” or “peer-based harm reduction services” or “overdose prevention education” or “overdose response training” or “naloxone training program*” or “opioid overdose education” or “recognizing and responding to overdose*” or “overdose prevention initiative*” or “access to healthcare service*” or “healthcare for people who use drugs” or “substance abuse treatment access” or “integrated healthcare for substance use disorder*” or “addiction treatment service*” or “medical service* for substance abuser*” or “harm reduction policies and advocacy” or “public health campaign*” or “harm reduction in prison*” or “harm reduction psychotherapy” or “testing and treatment for blood-borne diseases” or “peer education and safer use practice*” or “peer support and peer distribution programs” or “risk mitigation” or “minimizing harm” or “injection safety” or “drug-related harm reduction” or “substance use harm reduction” or “health protection strategies” or “public health approaches to substance abuse” or “drug-related harm prevention” or “safe disposal of drug paraphernalia” or “opioid overdose reversal” or “managed drug consumption site*”. Supplement 1 provides all keywords used in the search string. Boolean operators (e.g., and, or) were used to refine the search and capture relevant articles.

Inclusion and exclusion criteria

The retrieved articles were screened based on specific inclusion and exclusion criteria. Inclusion criteria encompassed research articles published in peer-reviewed journals, written in English, and published at any time between 1980 and December 31st, 2022. Exclusion criteria involved articles that were not directly related to harm reduction in the context of IDU. For example, articles related to articles related to alcohol, tobacco, or smoking were excluded.

Absence of false positive results

The top 40 cited articles were thoroughly reviewed to verify their relevance to the field of harm reduction interventions for substance use. Each article was assessed to confirm that it addressed the research topic and contained information pertinent to the study objectives. The absence of false positive results within the top 40 cited articles provided confidence in the accuracy of the search strategy. To further verify the absence of false-positive results, a random sample of 20 articles was screened, and no false positives were found. This sample was chosen by selecting every 10th article after sorting the articles based on the year of publication.

Active journals within the field

Scopus provides the names of journals involved in publishing the retrieved articles. Journals that published the highest number of articles (active journals) were examined to assess their relevance and standing within the field of substance use. In the current study, the International Journal of Drug Policy , Harm Reduction Journal , and Drug and Alcohol Dependence were most active within the field indicating that the implemented methodology was abe to identify sources that publish research articles in the area of interest.

Active authors within the field

Scopus provides the names of authors with the highest number of publications in a given set of data. Authors with the highest number of publications (active authors) were assessed to ensure that their expertise and research interest were in the field of harm reduction in general. In the current study, Scopus profiles of active authors indicated that the research field and interests of active authors indicated that the search methodology was able to identify key contributors within the field.

Comprehensive coverage

The comprehensiveness of the search strategy was tested by conducting a cross-validation with an alternative source. To validate the scope of the search strategy, ten articles were randomly selected from Google Scholar, a commonly used academic search engine, that had the term “harm reduction” and “substance use”. These ten articles were then searched for within the retrieved articles from Scopus. The presence of all ten articles in the retrieved dataset indicated the thoroughness and comprehensiveness of the search strategy.

Correlation testing

Based on the search strategy, Scopus provides the list of authors involved in published the retrieved articles. In the current study, Vickerman, P., Des Jarlais D.C., Strathdee, S.A., Maher, L. and others were the most active. For each active author, Scopus denotes the number of articles contributed by each active author to the field. To confirm the validity of the search strategy, we tested the correlation between the numbers of articles provided by Scopus for the top 10 active authors with the number of articles for the same authors counted manually in Google Scholar. In the current study, there was a significant correlation ( p  = 0.019) with a Pearson correlation of 0.83. This indicated high validity and comprehensiveness of the search strategy. This method was adopted from previously published methodology in the field of research landscape analysis [ 19 ].

Data analysis

Growth pattern of publications and key contributors to the retrieved articles.

They were identified by exporting the retrieved articles from Scopus to Microsoft Excel, sorted, and presented. Key contributors included active authors, countries, journals, and institutions. In the current study, the term “active” refers to the those with highest number of publications.

VOSviewer maps

In the current study, three types of maps were created using VOSviewer [ 20 ], a software tool for visualizing and analyzing networks. Interpreting VOSviewer maps involves understanding how different elements of academic literature are visually represented. The author-author collaboration network map illustrates the relationships and collaborations between authors within a specific field. Each node represents an author, and the links between nodes indicate collaboration, typically through co-authorship of papers. Larger nodes indicate authors with more publications or greater centrality in the network, suggesting they are key figures or highly productive researchers in the field. Thicker or more numerous links between nodes suggest stronger or more frequent collaborations, while a dense cluster of links implies a tight-knit group of authors who frequently collaborate. Authors who collaborate frequently with each other tend to form clusters, represented by different colors, which may correspond to a subfield or a specific research group within the larger field. Isolated nodes indicate authors without links, suggesting they have not collaborated with others in the dataset or have fewer collaborative ties. The map of most frequent author keywords shows the keywords that authors use most frequently in their publications, helping identify the main topics and trends within the research field. Larger nodes represent more frequently used keywords, indicating prominent topics or themes in the literature. Links between keywords show how often they appear together in the same articles, with stronger or more frequent links suggesting a close relationship between those topics. Keywords that frequently co-occur form clusters, usually represented by different colors, signifying thematic areas or specific research topics within the field. High-density areas on the map indicate heavily researched topics with many publications, often central themes in the field. The map of most frequent terms in titles and abstracts highlights the most common terms found in the titles and abstracts of the publications, providing insights into the primary focus and content of the research. Larger nodes represent terms that appear more frequently in titles and abstracts, highlighting key concepts and focal points of the research. Links between terms show how often they appear together in the same titles or abstracts, with stronger or more frequent links indicating these terms are commonly associated with each other. Terms that frequently co-occur are grouped into clusters, each represented by a different color, revealing conceptual areas or common themes within the research field. Central terms are those that appear frequently and are connected to many other terms, suggesting they are core concepts in the field, while peripheral terms are less frequent and may represent niche or emerging topics. VOSviewer often uses color coding to represent different clusters or groups, and understanding the color legend is essential for interpreting the map accurately. The overlay visualization feature can show temporal trends by mapping the average publication year of items, helping identify emerging trends or shifts in research focus over time. The density visualization highlights areas with a high concentration of items, indicating popular or heavily researched topics. VOSviewer allows users to interact with the map, such as zooming in and out or clicking on nodes for more information, enabling a thorough exploration of details and relationships. By carefully examining these maps, researchers can gain valuable insights into collaboration patterns, research trends, and key topics within their field of interest.

Research hotspots identification

To identify research hotspots, the ones with high influence and impact in the field, the top 50 cited articles were screened to identify the top main five research topics.

Identification of emerging research directions

To identify the current research topics and potential future research directions, analysis of the recently published 50 articles was conducted.

Growth of publications and key contributors to the retrieved articles

Based on the search strategy outlined in Supplement 1 and flow chart in Supplement 2 , a total of 971 articles on harm reduction in the context of IUD were found. Scopus provides categorization of the retrieved articles into different subject areas, based on the scope of each journal. The majority of the retrieved articles were published in journals within the subject area of medicine ( n  = 881, 90.7%), indicating a strong focus on the medical aspects of IDU and harm reduction. Other significant subject areas included social sciences ( n  = 150, 15.4%) and psychology ( n  = 93, 9.6%), highlighting the multidisciplinary nature of research in this field. The number of publications over time showed a slow upward fluctuating increase up to 2014, followed by a steeper increase from 2015 up to 2022 (Fig.  1 ).

Annual growth of publications on harm reduction research in the context of injectable drug use (1980–2022)

The International Journal of Drug Policy emerged as the most prolific journal with 172 (17.7%) articles, followed by Harm Reduction Journal ( n  = 104, 10.7%) and Drug and Alcohol Dependence ( n  = 38, 3.9%). These three top journals contributed 314 (32.3%) articles to the retrieved literature making them key players in the field. The top 10 active journals were in the field of substance use, drug policy, AIDS, and public health.

Scopus provides the country affiliation of each author present in the retrieved articles. Based on this, 83 different country affiliations were found suggesting that scholars from 83 different countries participated in publishing the retrieved articles. The United States, as a country affiliation, had the highest number of publications with 558 articles, accounting for 57.5% of the total. The United Kingdome (UK), Canada, and Australia made significant contributions ranging from 118 to 123 articles for each. However, it’s important to highlight that 41 (49.4%) countries contributed three or fewer articles each, indicating a need for more global research collaboration and participation. Among the institutions, Johns Hopkins University ranked as the most prolific with 80 (8.2%) articles, followed by UNSW Sydney ( n  = 60, 6.2%), and the University of British Columbia ( n  = 51, 5.2%). The retrieved articles involved a total of 3,847 authors, resulting in an average of 4.0 authors per article. Authors with a minimum contribution of 10 articles and exist in a collaborative research network are shown in Fig.  2 . The node size of each author is proportional to his/her research contributions. Authors with similar node colors have common research interest. More than one third ( n  = 345, 35.5%) of the published articles were funded by the National Institutes of Health (NIH), highlighting their support and investment in research related to harm reduction interventions.

Network visualization map of authors with a minimum contribution of 10 articles and exist in a collaborative research network. The node size of each author is proportional to his/her research contributions. The figure was created by the author using VOSviewer

Mapping frequent author keywords and frequent terms in titles/abstracts

In this study, the VOSviewer technique was utilized to generate a map of author keywords that appeared at least 10 times in the collected literature. The resulting map (Fig.  3 ) consisted of 52 frequently occurring author keywords. The size of each node in the map corresponds to the frequency of occurrence of the respective keyword in the literature. Among the identified keywords, the ones related to harm reduction and IDU were the most frequent followed by those related to HIV, hepatitis C (HCV), and opioid overdose. VOSviewer visualization technique was also used to map frequent terms in the titles and abstracts of the retrieved articles. The map (Fig.  4 ) shows the frequent terms distributed into three major clusters based on node colors. The major research themes were related to harm reduction in the context of HCV (blue cluster), HIV (red cluster), and opioid overdose (green). These represent the main research themes addressed in the retrieved literature.

Network visualization map of author keywords that appeared at least 10 times in the collected literature. The map consisted of 52 frequently occurring author keywords. The size of each node in the map corresponds to the frequency of occurrence of the respective keyword in the literature

Network visualization map of frequent terms in the titles and abstracts of the retrieved articles. The map shows that the frequent terms were distributed into three major clusters based on node colors. The major research themes were related to harm reduction in the context of HCV (blue cluster), HIV (red cluster), and opioid overdose (green). These represent the main research themes addressed in the retrieved literature

Research topics in the top 50 cited articles and top 50 recently published articles

Analysis of the top 50 cited articles (Supplement 3 ) indicated the presence of 10 research topics (Table  1 ). Based on the title/abstract of the top 50 cited articles, the largest research topic was related to the distribution of naloxone, a medication used to reverse opioid overdoses, and the prevention of opioid overdose deaths. Naloxone distribution programs aim to increase access to naloxone and educate laypersons on its use to save lives in the event of an overdose. This topic directly relates to harm reduction by reducing opioid-related deaths. Analysis of the top 50 recently published articles (Supplement 4 ) indicated the presence of 9 research topics (Table  2 ). The largest research topic focused on strategies, interventions, and policies aimed at preventing opioid overdose, including naloxone distribution programs, overdose risk mitigation, overdose prevention training, and opioid overdose counseling. Differences between the nature and content of research topics in the 50 most cited articles and the 50 most recently published articles reflect the differences in research interest and research focus over time. The differences are summarized below:

Time period: The research topics in the 50 most cited articles appear to cover a more extensive time span, possibly ranging from earlier years up to the present. On the other hand, the research topics in the 50 most recently published articles are focused on current and emerging issues in the field, likely reflecting more recent developments in harm reduction efforts.

Focus on naloxone distribution: Naloxone distribution and overdose prevention emerge as a prominent research topic in the highly cited articles, with 9 articles dedicated to this subject. In contrast, while opioid overdose prevention is still a prevalent topic in the recently published articles, it is not as dominant as in the highly cited articles.

HIV and Hepatitis C transmission: In the highly cited articles, HIV transmission and injection drug use, as well as hepatitis C transmission and injection drug use, are prominent research topics, with 8 and 7 articles, respectively. While HIV prevention and service delivery for people who inject drugs and hepatitis C virus (HCV) prevention and treatment are also relevant topics in the recently published articles, they seem to have slightly less emphasis compared to the older publications.

COVID-19 pandemic impact: The impact of the COVID-19 pandemic on people who inject drugs emerges as a research topic in the recently published articles, which is not present in the highly cited articles. This indicates a focus on understanding and adapting harm reduction efforts during public health emergencies.

Social network analysis and mathematical modeling: The use of social network analysis and mathematical modeling to understand HIV transmission dynamics among people who inject drugs is more pronounced in the recently published articles, whereas it is not as prominently featured in the highly cited articles.

Fentanyl-related concerns: Articles investigating fentanyl-related concerns and risks associated with fentanyl use are notable research topics in the recently published articles, which may reflect the growing concern over fentanyl’s impact on opioid overdose deaths.

Stigma reduction and attitudes: Research topics related to stigma reduction and attitudes toward opioid use disorder appear in the recently published articles, highlighting the importance of addressing social barriers and negative perceptions that can hinder harm reduction efforts.

Needle and Syringe Programs: While needle and syringe programs are still relevant in both sets of articles, they appear to be more explicitly explored in the recently published articles, indicating ongoing interest in this harm reduction strategy.

Overall, the research topics in both sets of articles share a common focus on harm reduction strategies and interventions. However, the more recent articles seem to emphasize emerging challenges, such as fentanyl-related risks and the impact of the COVID-19 pandemic, while the highly cited articles encompass a broader time frame and may have laid the foundation for some of the harm reduction efforts seen in the more recent publications.

The current study analyzed and mapped the research activity on harm reduction in the context of IDU. The analysis showed steady growth over time, which can be attributed to the increased spread of HIV and HCV among people who inject drugs. This public health crisis highlighted the urgent need for effective harm reduction interventions, such as needle and syringe exchange programs, to prevent the transmission of these blood-borne infections. The increasing research focus can also be attributed to the immediate need for evidence-based strategies to address the spread of HIV and other infectious diseases transferred through contaminated needles [ 21 , 22 , 23 , 24 , 25 ]. The steeper growth in research from 2015 to 2022 may reflect the increased demand for evidence to inform the expansion and improvement of these interventions [ 9 , 26 , 27 , 28 ]. In recent years, there has been a growing recognition of the social determinants of drug use and related health disparities. This broader understanding acknowledges that substance use is influenced by complex social, economic, and structural factors [ 29 , 30 , 31 ]. Consequently, research on harm reduction interventions has expanded to examine the intersecting issues of poverty, inequality, stigma, mental health, and access to healthcare. This multidimensional approach has likely contributed to the increased research interest and the steeper growth observed in recent years. Overall, the growth pattern in research on harm reduction interventions in the context of IDU reflects a combination of factors, including increased recognition of the importance of harm reduction, the impact of HIV and HCV epidemics, policy and program expansions, evolving drug use landscapes, and a broader understanding of social determinants. This growth signifies the ongoing commitment to addressing the complex challenges faced by individuals who inject drugs and the continuous efforts to develop effective interventions that prioritize harm reduction and public health.

The current study showed that research activity on harm reduction in the context of IDU was mainly limited to high-income, English-speaking countries. The reasons for research activity in the field of harm reduction interventions in different countries are multifaceted, involving factors such as the prevalence of IDU, research capacities, government support, international collaboration, and unique socioeconomic and cultural contexts [ 32 , 33 , 34 , 35 ]. It is a combination of these factors that contribute to the research focus in specific countries. The fact that the Harm Reduction journal and the International Journal of Drug Policy rank highly and contribute to approximately one third of the research output on harm reduction interventions in the context of IDU indicates their significant role and influence in this area of study. This research activity can be interpreted as a reflection of the growing recognition of the importance of harm reduction approaches in addressing the complex issues associated with IDU. These journals’ focus on harm reduction aligns with the broader shift in drug policy and public health approaches towards a more compassionate and evidence-based approach to drug use. Harm reduction recognizes that complete eradication of drug use may not be feasible, and instead aims to minimize the harms and risks associated with drug use for both individuals and communities. The research output in this field may be driven by several factors. Firstly, there is a pressing need to develop effective interventions to address the increasing rates of IDU and related health risks, including HIV and hepatitis C transmission. Harm reduction interventions, such as needle and syringe programs, naloxone distribution, and opioid agonist treatment, have shown to be effective in reducing these harms [ 36 , 37 ]. Secondly, the research activity may be driven by the urgency of the opioid crisis and its devastating impact on individuals, families, and communities [ 38 , 39 , 40 ]. The opioid crisis has heightened public awareness and policymakers’ attention to the need for evidence-based strategies, such as harm reduction, to address the escalating overdose rates and associated mortality. Furthermore, the research activity may be influenced by the recognition that criminalization and punitive approaches have proven ineffective in reducing drug-related harms and have contributed to the stigmatization and marginalization of drug users. Harm reduction provides an alternative framework that emphasizes public health, human rights, and social justice, which resonates with researchers, policymakers, and advocates seeking more humane and effective solutions [ 41 , 42 , 43 ]. The research output in these journals reflects the interdisciplinary nature of harm reduction, drawing on fields such as public health, medicine, social sciences, and policy studies. It highlights the collaborative efforts of researchers, practitioners, and policymakers to generate evidence, evaluate interventions, and inform policy and practice. In summary, the prominence of the Harm Reduction journal and the International Journal of Drug Policy in the research output on harm reduction interventions in the context of IDU indicates the significance and relevance of this research area. It reflects the growing recognition of harm reduction as a compassionate and evidence-based approach to addressing the complex challenges associated with IDU, particularly in the context of the opioid crisis and the need for effective interventions to reduce harm and improve public health outcomes.

The major common research points between the highly cited articles and the recently published articles include a focus on harm reduction strategies, interventions, and policies related to opioid overdose prevention, HIV prevention and service delivery for people who inject drugs, HCV testing and treatment, and needle and syringe programs. These areas of research demonstrate the ongoing efforts to address the complex challenges associated with substance use, harm reduction, and public health. Both sets of highly cited and recently published articles share a common goal of advancing harm reduction efforts and improving the health and well-being of individuals who inject drugs. However, there were certain important differences in the two sets that can be attributed to the time difference. The highly cited articles cover a broader time span, including earlier years up to the present, whereas the recently published articles are focused on current and emerging issues. This difference reflects the evolving nature of research interests and the changing landscape of harm reduction efforts over time. Naloxone distribution and overdose prevention appear as a prominent research topic in the highly cited articles [ 44 , 45 ]. This likely reflects the increasing recognition of naloxone as a life-saving intervention for opioid overdoses and the efforts to expand access to this medication. In the recently published articles, while naloxone distribution and overdose prevention remain relevant, they may not be as dominant due to the maturation of research in this area. The highly cited articles give considerable attention to HIV and hepatitis C transmission among people who inject drugs, indicating the historical significance of these issues and the focus on preventing the spread of bloodborne infections [ 46 , 47 , 48 ]. While HIV prevention and HCV prevention and treatment are still prominent research topics in the recently published articles, they may have slightly less emphasis compared to the older publications, reflecting advancements and progress made in these areas. The recently published articles include research on the impact of the COVID-19 pandemic on people who inject drugs and harm reduction services [ 49 , 50 , 51 ]. This research topic is not present in the highly cited articles, indicating a response to the ongoing public health crisis and the need to understand and adapt harm reduction efforts during such emergencies. The use of social network analysis and mathematical modeling to study HIV transmission dynamics among people who inject drugs is more pronounced in the recently published articles [ 52 , 53 , 54 , 55 ]. This reflects the increasing recognition of the role of social networks and complex systems in understanding disease transmission and designing targeted interventions. Articles investigating fentanyl-related concerns and risks associated with fentanyl use emerge as notable research topics in the recently published articles [ 56 , 57 ]. This reflects the growing concern over fentanyl’s role in the opioid crisis and its impact on opioid overdose deaths, indicating a need for research to address this specific challenge. The recently published articles include research topics related to stigma reduction and attitudes toward opioid use disorder [ 58 , 59 ]. This highlights the recognition that addressing stigma and negative perceptions is crucial for effective harm reduction strategies and improving access to services. While needle and syringe programs remain relevant in both sets of articles, they appear to be more explicitly explored in the recently published articles. This may reflect a continued interest in evaluating the effectiveness and impact of these harm reduction strategies and exploring their implementation in different contexts.

Research/knowledge gaps

Based on the research topics and mapping of keywords and items in titles and abstracts of the retrieved articles, several research gaps can be identified in the context of harm reduction for injecting drug users (IDU). Firstly, there is a limited focus on low- and middle-income countries, as the current study reveals that research activity on harm reduction interventions is primarily concentrated in high-income, English-speaking countries. More research is needed in low- and middle-income regions where IDU and associated harms may be prevalent but inadequately addressed. Secondly, with the evolving landscape of drug use, including the emergence of new substances like synthetic opioids such as fentanyl, more research is necessary to understand their impact on harm reduction interventions and to develop effective strategies to mitigate their potential harms. Additionally, a comprehensive understanding of social determinants is crucial. While recent research recognizes the influence of social determinants on drug use and related health disparities, further investigation is required to better understand and address the complex interactions of poverty, inequality, stigma, mental health, and access to healthcare in harm reduction contexts. There is also a need for rigorous evaluation studies to assess the long-term impact and cost-effectiveness of harm reduction interventions, such as needle and syringe programs, naloxone distribution, and opioid agonist treatment, in various settings. Furthermore, research gaps exist in understanding the unique needs and challenges faced by marginalized and vulnerable populations, including women who inject drugs, LGBTQ + communities, and racial or ethnic minorities. Tailored harm reduction interventions that address these groups’ specific needs are essential for equitable access to services. There is also a lack of longitudinal studies tracking the implementation and effectiveness of harm reduction interventions over time. Long-term studies are necessary to monitor trends, evaluate progress, and identify areas for improvement. Moreover, comparative studies across different harm reduction approaches and models can help identify the most effective strategies for specific populations and settings. Comparative effectiveness studies can contribute to evidence-based policymaking and program implementation. Lastly, further research is needed to understand the barriers and facilitators of implementing harm reduction programs and policies on a broader scale. Identifying successful implementation strategies can support the uptake of evidence-based interventions in various contexts. Addressing these research gaps can enhance the effectiveness and impact of harm reduction interventions for IDU, contributing to improved public health outcomes and reduced harm for individuals and communities affected by drug use.

Limitations

The use of Scopus as the primary data source may result in the exclusion of articles from other databases or gray literature sources. This could introduce a potential bias in the findings. The study focused on articles published in English, which may lead to the exclusion of relevant non-English publications. The analysis of recently published articles was based on a specific time frame, and therefore, the identified emerging topics and future directions may not capture the entire spectrum of ongoing research in the field. The inclusion and exclusion criteria used for article screening may introduce some degree of selection bias, potentially omitting relevant studies. The absence of false-positive and false-negative results was based on several validity tests that ensures the comprehensiveness of research strategy but no guarantee of the accuracy of the retrieved articles remained less than perfect. This should not be considered a major drawback in a study that focus on research patterns and trends rather than on a specific research question as in the case of systematic review. Finally, the research gaps provided in the current study was based on research mapping rather than screening the articles themselves. Therefore, these research gaps remain an overall picture of the research status rather than specific detailed research gaps based on the content analysis of the articles.

In conclusion, this study has provided valuable insights into the research activity on harm reduction in the context of IDU. The findings demonstrate steady growth in research over time, driven by various factors. The increasing recognition of the importance of harm reduction approaches, the impact of HIV and HCV epidemics, the development of policies and programs, the evolving drug use landscape, and a broader understanding of social determinants have all contributed to the growth of research in this field. The study also revealed that research activity is primarily concentrated in high-income, English-speaking countries, highlighting the need for more research in low- and middle-income countries. The prominence of journals such as the Harm Reduction journal and the International Journal of Drug Policy indicates their significant role in shaping this field of study and aligns with the broader shift towards evidence-based and compassionate approaches to drug use. Common research areas between highly cited and recently published articles include opioid overdose prevention, HIV prevention, HCV testing and treatment, and needle and syringe programs, reflecting the ongoing commitment to harm reduction efforts. However, recent publications have focused more on emerging challenges such as the impact of the COVID-19 pandemic, fentanyl-related risks, stigma reduction, and attitudes toward opioid use disorder. The identified research gaps call for further research in low- and middle-income countries, addressing new and emerging substances, comprehensive understanding of social determinants, evaluating program effectiveness, including diverse populations, conducting longitudinal and comparative studies, and investigating implementation strategies. Addressing these gaps will contribute to the development of more effective interventions and policies that prioritize harm reduction and public health, ultimately improving the well-being of individuals who inject drugs and the communities they belong to.

Data availability

All data presented in this manuscript are available on the Scopus database ( www.scopus.com ) using the search query listed in the methodology section.

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Sweileh, W.M. Analysis and mapping of harm reduction research in the context of injectable drug use: identifying research hotspots, gaps and future directions. Harm Reduct J 21 , 131 (2024). https://doi.org/10.1186/s12954-024-01048-0

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ORIGINAL RESEARCH article

The role of product market competition and analyst attention in modulating the link between equity pledges and classification shifting.

• 1 School of Business and Economics, Universiti Putra Malaysia, Serdang, Malaysia
• 2 Department of Finance and Economics, Liupanshui Vocational and Technical College, Liupanshui, China

This study investigates the association between equity pledges and classification shifting earnings management in Chinese listed firms, spanning the period from 2016 to 2022. Additionally, it explores the moderating influence of product market competition (PMC) and analyst attention on this relationship. By analyzing a sample comprising 12,583 firm-year observations, several notable findings are observed. The regression results reveal a positive and statistically significant relationship between equity pledges and classification shifting earnings management (coefficient = 0.00234, p < 0.01). Moreover, this positive impact is further magnified when specifically considering downward classification shifting (coefficient = 0.00368, p < 0.01). Regarding the moderating factors, the results demonstrate a positive moderating effect of PMC on the relationship between equity pledges and classification shifting, with an interaction coefficient of 0.0165 ( p < 0.01). This moderating effect is particularly pronounced in the context of downward classification shifting, with an interaction coefficient of 0.0142 ( p < 0.01). Similarly, analyst attention also positively moderates the relationship, as indicated by an interaction coefficient of 0.00144 ( p < 0.05), with a stronger effect observed in the case of downward classification shifting, with an interaction coefficient of 0.00329 ( p < 0.01). Furthermore, additional tests reveal that leverage strengthens the aforementioned moderating effects. The three-way interaction involving debt, PMC, and equity pledges significantly influences classification shifting, with a coefficient of 0.0415 ( p < 0.05). Specifically, debt exacerbates the moderating impact of competition on highly leveraged firms that engage in downward classification shifting, as evidenced by a coefficient of 0.0599 ( p < 0.05). Similarly, debt reinforces the moderating role of analyst attention (coefficient = 0.00820, p < 0.05), especially for downward classification shifting (coefficient = 0.00902, p < 0.1). Propensity score matching and robustness tests validate the findings. Therefore, this research contributes to the understanding of the economic implications of equity pledge by focusing on earnings manipulation through classification shifting. It also examines this relationship within different competitive environments and external regulatory frameworks, aiming to promote the long-term viability of companies.

1 Introduction

Since the implementation of the equity pledge system in 2013, there has been a significant rise in the participation of companies in equity pledges ( Wang and Chou, 2018 ; Zhu et al., 2021 ; Ye, 2024 ). According to data from the wind database, as of August 2022, over half of the Chinese A-share companies still had active equity pledges ( Liu C. et al., 2023 ). Anderson and Puleo ( Anderson and Puleo, 2020 ) argue that maintaining the firm’s performance and ensuring a stable share price during the pledge period is crucial for the pledgee, creating a strong motivation for earnings management.

In recent times, there has been considerable scholarly interest in the phenomenon of earnings management, encompassing both accrual-based and real earnings management strategies ( García Sánchez et al., 2020 ; Hu et al., 2024 ; Wang et al., 2024 ). Nonetheless, McVay ( McVay, 2006 ) has identified a distinct third strategy called classification shifting earnings management, which is frequently observed within the realm of the capital market. Song et al., 2015 found that this strategy is relatively common among Chinese listed companies. Nevertheless, limited research has been conducted on this method in the Chinese context. Given the information asymmetry between the pledger and the pledgee during the stock pledging process, it raises the question of whether the pledgee utilizes classification shifting earnings management to take advantage of the pledger.

In recent years, heightened economic uncertainty has led to increased market competitiveness ( Purwaningsih et al., 2024 ; Sheikh et al., 2024 ; Tu et al., 2024 ). In such a fiercely competitive environment, companies face a greater need for capital and a stronger motivation to exercise control over their earnings. On the one hand, organizations endeavor to safeguard their information to prevent leaks and defend against predatory actions by their competitors. Conversely, due to the pervasive presence of competitors within the industry, attaining flawless regulation becomes a challenging task. Consequently, in fiercely competitive markets, the majority of companies that have equity pledges resort to employing accrual-based or real income management methods ( Yung and Nguyen, 2020 ). However, as these two methods of surplus management have gained popularity, they have also attracted the attention of external financial report users. Consequently, firms may employ more clandestine approaches, such as classification shifting earning management, to maneuver within the limited operational space available to them ( Haveman et al., 2023 ; Sadaf et al., 2023 ). Hence, it is crucial to examine the association between equity pledges and classification shifting earnings management within the framework of product market competitiveness. The practice of earnings management during the equity pledge process arises from the inherent information asymmetry between the pledging company and the pledgee ( Agstner, 2020 ; Xie and Zhang, 2021 ). The issue of information asymmetry can be effectively resolved by the information mining function performed by market information intermediaries, with analysts assuming a vital role as intermediaries who bridge the gap between investors and listed companies ( Zhao et al., 2023 ). Therefore, it is essential to examine the moderating influence of analysts’ attention on the relationship between equity pledges and the management of classification shifting earnings.

Firstly, product market competition serves as a significant external factor that can shape the effectiveness of corporate disclosure and the incentives for earnings management. As market competition intensifies, companies with equity pledges may face heightened pressure to safeguard sensitive information and differentiate themselves from competitors, leading to an increased likelihood of engaging in more covert forms of earnings manipulation, such as classification shifting. While the existing literature has explored the influence of PMC on earnings management practices, its moderating effect in the specific context of equity pledges and classification shifting has remained understudied. This study aims to contribute to the understanding of how competitive market dynamics can shape the earnings management strategies employed by firms with equity pledges. Secondly, analysts play a crucial role as information intermediaries and external governance mechanisms in the capital market. The attention and scrutiny of analysts can have a significant impact on corporate reporting practices and the quality of financial information disclosed to investors. In the context of equity pledges, where information asymmetry between the pledgor and pledgee is a concern, analysts can bridge this gap and potentially influence the incentives for earnings management. However, the existing literature has presented mixed findings on the moderating effect of analyst attention, with some studies suggesting a positive impact on earnings quality and others highlighting the potential for manipulation. By examining the moderating influence of analyst attention on the relationship between equity pledges and classification-shifting earnings management, this study aims to provide valuable insights into the complex dynamics between corporate disclosure, external monitoring, and earnings management in the presence of equity pledges. Moreover, this study also investigates the interplay between the two moderating factors, PMC and analyst attention, alongside the level of firm leverage. Highly leveraged firms with equity pledges may face heightened operating pressures and scrutiny from stakeholders, potentially amplifying the moderating effects of PMC and analyst attention on their classification-shifting earnings management practices. Exploring these three-way interactions contributes to a more comprehensive understanding of the nuanced relationships and the specific conditions under which equity pledges are associated with increased earnings manipulation through classification shifting. By focusing on these two moderators and their distinguished significance, this study contributes to the existing literature in several important ways. Firstly, it enhances our understanding of the economic implications of equity pledges by providing insights into the specific earnings management strategies, such as classification shifting, that may arise in the presence of these corporate financing arrangements. Secondly, it expands the application of PMC and analyst attention as important contextual factors that can shape earnings management practices, particularly in the underexplored area of classification shifting. Finally, it examines the interplay between these moderating factors and firm leverage, shedding light on the complex dynamics that may influence the earnings management behaviors of highly leveraged firms with equity pledges.

This research adds value to the current body of knowledge in various significant areas. Firstly, it delves into the correlation between equity pledges and the management of classification shifting earnings, thereby enhancing our comprehension of the economic implications associated with firms’ behavior of pledging equity. Secondly, it investigates the moderating role of PMC within the context of equity pledges and the management of classification shifting earnings, thereby expanding the application of PMC in this specific domain. Thirdly, it sheds light on the impact of analysts’ attention on both equity pledges and the management of classification shifting earnings. Fourthly, this research examines the influence of leverage on the aforementioned moderating effects (PMC and analyst attention). Lastly, to ensure the robustness of the findings, the study conducts thorough tests for both robustness and endogeneity. The subsequent sections of this research are structured as follows: Section 2 offers an extensive examination of the pertinent literature and introduces the formulation of the hypotheses. Section 3 delineates the approach employed, encompassing sample selection, variable formulation, and model specification. Section 4 presents the findings derived from descriptive statistics, correlation analysis, regression analysis, as well as tests conducted to address endogeneity and ensure robustness. Lastly, Section 5 concludes the study by summarizing the main findings and proposing potential avenues for future research.

2 Review of previous studies and Formation of hypotheses

2.1 review of existing literature, 2.1.1 equity pledge and manipulation of earnings.

Previous studies have established a noteworthy inverse association between equity pledges and earning quality, emphasizing the close relationship between the extent of equity pledges and earnings manipulation. When companies decide to pledge their equity, they often prioritize raising additional capital by enhancing share prices, which can lead to limited focus on the integrity of financial statements ( Duan et al., 2022 ; Zhang et al., 2022 ; Chen et al., 2023 ; Zhang et al., 2023 ). For instance, Chiou et al. ( Chiou et al., 2002 ) assert that the utilization of equity pledges by a company raises concerns about the reliability of its reported profits. In cases involving multiple pledges, shareholders may exert pressure on management to consistently generate higher levels of funds. Expanding upon Chiou et al., 2002 , Blankespoor, 2022 subdivides the sample and discovers that firms exhibiting strong performance and robust financial statements are more likely to attract favorable attention from investors. Consequently, numerous companies adjust their operational performance through the implementation of accounting policies and other strategies to secure additional funding. However, Dichev et al., 2013 highlight the potential severe consequences of such practices, including compromised statement credibility, deteriorated earnings quality, and misleading information for investors.

2.1.2 The moderating influence of PMC

He influence of market competition on the manipulation of firms’ financial statements has attracted considerable interest from researchers. Fama et al. ( Fama and French, 2008 ) assert that as market competition intensifies, investors have the opportunity to analyze the actual operating conditions of investee companies by comparing financial data with other firms in the same industry. This process mitigates information asymmetry, improves information transparency, and enables shareholders to accurately assess the operational capabilities and performance of the company. Moreover, investors assimilate this information, resulting in increased scrutiny of corporate management as market competition intensifies, thus discouraging the adoption of earnings management practices ( Hadani et al., 2011 ; Bashir et al., 2024 ).

2.1.3 The role of analyst attention and PMC as moderators

Diverse perspectives exist among scholars regarding the moderating effect of analyst attention. Some argue that firms that prioritize analyst attention tend to exhibit higher-quality earnings and a reduced need for earnings management. Yu ( Yu, 2008 ) investigates companies listed in the United States and provides evidence that a higher degree of uniformity in accounting standards and treatment imposes greater pressure on management to disclose accurate and reliable accounting information. This, in turn, enhances the comparability of accounting information and reduces the incentive for earnings management. Several studies highlight that securities analysts incorporate the adverse effects of information manipulation, including earnings management, into their research and analysis reports as a means to safeguard the reputation of the company ( Baskaran et al., 2020 ; Palacios-Manzano et al., 2021 ). This serves to diminish the motivation for earnings management, enhance the quality of corporate accounting information, and increase comparability ( Xi et al., 2022 ; Duan and Li, 2023 ; Wang et al., 2023 ; Zhu et al., 2023 ; Liu et al., 2024 ). However, another group of scholars suggests a negative effect of analyst attention on corporate governance. Irani et al. ( Irani and Oesch, 2016 ) reveal that managers have the capacity to manipulate actual levels of earnings management in order to align with analysts’ earnings estimates, thereby impacting the quality of corporate accounting information. In the context of heightened external oversight, such as analyst attention, Lennox et al., 2018 investigate a sample of listed companies in China and observe that management resorts to covert earnings management practices to safeguard their personal reputation and sustain share prices. As a result, this results in inconsistent disclosure of accounting information, with a more significant detrimental effect observed in state-owned enterprises.

After conducting a thorough analysis, it is apparent that previous studies have not delved into the correlation between equity pledges and earnings management through classification shifting. Moreover, the moderating influences of analyst attention and PMC have not been explored in either of these contexts. Therefore, this research aims to fill this void by comprehensively investigating these associations.

2.2 Hypothesis development

The interaction among the pledgor, the pledgee, and investors introduces potential inconsistencies, conflicts of interest, and the possibility of exploitation. The pledgor, possessing privileged access to specific business operation information, may strategically present selectively filtered and collected data to the pledgee and investors. This information asymmetry can lead to various outcomes. For instance, prior to the pledge, the pledgor might engage in earnings manipulation to artificially inflate the share price, creating an illusion of sustained profitability ( Marron, 2009 ). Consequently, if the share price experiences a significant decline following the pledge, the pledgee is confronted with the risk of increasing the pledge or exercising their rights, which may push the enterprise into financial distress or even lead to a change in ownership. This creates an agency problem that incentivizes false reporting and earnings manipulation ( Gregova et al., 2021 ; Ustinova, 2023 ).

Investors determine the amount of capital they will provide to a company based on the share price at the time of pledging. Consequently, companies strive to increase the share price to secure more capital. According to Christensen et al., 2022 , senior executives in corporations hold the belief that investors and the market are inclined to invest in companies that demonstrate robust operational performance and are willing to pay premium prices for their stocks. As a result, controlling shareholders may be motivated to misrepresent their management’s financial information to inflate the share price. The most practical approach to achieve this is by modifying and embellishing publicly disclosed earnings information. Dou et al., 2019 identified that companies employing judicious methods to manipulate profits can distort investors’ perceptions of risk, overstate the company’s performance, and facilitate financing and risk mitigation. Consequently, companies frequently resort to low-cost earnings management as a strategy to mitigate these concerns ( Ghazali et al., 2015 ; Luo et al., 2023a ; Luo et al., 2023b ; Gao et al., 2023 ). Subsequently, upon receiving the pledge, if earnings management ceases and the true operational results are disclosed, the share price may undergo substantial fluctuations, exposing the pledgor to the risk of additional pledges or liquidation. This establishes a potential environment for future earnings manipulation.

Classification shifting earnings management encompasses two directions: upward and downward, depending on the desired outcome. Upward classification shifting involves converting non-recurring losses into expenses or recurring income into earnings, thereby inflating core earnings ( Abiahu et al., 2019 ; Liu Y. et al., 2023 ). As external stakeholders enhance their knowledge of classification shifting earnings management and become more proficient in detecting such activities, companies are increasingly inclined to engage in downward categorical shifting of surplus management to stabilize core earnings. Building upon this, we put forward the following hypotheses:

H1a. The existence of equity pledges in publicly traded firms has a noteworthy influence on the degree of classification shifting earnings management.

H1b. Corporate equity pledges are associated with an increase in downward classification shifting earnings management.

PMC serves as an external factor that impacts the effectiveness of insider disclosure. As market competition intensifies and companies face increased capital requirements, the divergence between management and shareholders’ interests may worsen, leading management to prioritize their own interests over those of the company’s shareholders when making critical decisions ( Ho, 2010 ; Smith and Rönnegard, 2016 ). Consequently, the motivations for earnings management by management are intensified subsequent to the initiation of equity pledges. On one hand, they aim to safeguard sensitive information from disclosure and deter predatory actions by competitors. On the other hand, the presence of a multitude of competitors in the industry creates challenges in achieving complete regulation. Consequently, a significant proportion of companies with equity pledges are inclined to employ accrual or real earnings management techniques when operating within competitive markets ( Deren and Ke, 2018 ; Orazalin and Akhmetzhanov, 2019 ; Sajjad et al., 2019 ). However, as these earnings management practices become increasingly prevalent, companies may turn to more covert forms of classification shifting as the opportunities for manipulation diminish ( Feng et al., 2009 ; Cross, 2011 ).

In contrast, under conditions lacking market competition, an oligopolistic environment may emerge wherein all parties conform to stringent regulations due to minimal pressure and diminished motivation for earnings management. Consequently, the association between equity pledges and classification shifting earnings management is anticipated to be more pronounced in the presence of PMC. Additionally, competition within the product market can incentivize companies to adopt strategies focused on efficiency. As competition intensifies, excessive profits diminish, leading to a substantial reduction in industry-wide profits. Listed companies that possess equity pledges encounter higher repayment pressures and are more inclined to engage in downward classification shifting earnings management as a means to mitigate the adverse impact on stock prices and maximize short-term value in response to PMC.

Based on the aforementioned, the following hypotheses can be postulated:

H2a. PMC positively moderates the linkage between equity pledges and classification shifting earnings management.

H2b. The moderating effect of PMC primarily manifests in the association between equity pledges and downward classification shifting earnings management.

The influence of equity pledges on earnings management is contingent upon the attention received from analysts, as substantiated by theories of information asymmetry and signaling. Analysts, as important information intermediaries and external governance mechanisms in the capital market, have significant influence through their access to information and the signals they transmit. Their attention can also shape the way earnings are managed during the equity pledging process ( Orazalin and Akhmetzhanov, 2019 ; Puleo and Kozlowski, 2021 ). Based on the regulatory hypothesis, analysts closely monitor certain listed companies over an extended period and are likely to detect accrual earnings management behaviors during major shareholders’ share reduction activities. Additionally, analysts play a role in the external information disclosure process of corporate governance by disseminating research findings and earnings forecasts, which enhances transparency and effectively deters opportunistic earnings management during the equity pledging process ( Bhat et al., 2006 ; Li et al., 2020 ).

In recent years, there has been a growing focus on real earnings management, leading to increased scrutiny and limitations on its practices. However, graded shifting earnings management, which involves manipulating the profit structure to enhance or reduce core profits, faces fewer external constraints, is challenging to detect, and does not violate any legal or regulatory requirements. There exists a clear link between classification shifting earnings management, real earnings management, and accrual earnings management. During the process of equity pledging, corporate managers tend to employ covert classification shifting earnings management techniques when analysts raise concerns about the suppression of accrual and real earnings management, aiming to maximize the benefits derived from the pledge ( Zang, 2012 ; Enomoto et al., 2015 ; Sohn, 2016 ).

According to stress theory, investors heavily rely on analysts’ research reports and profit forecasts when making investment decisions ( Zahera and Bansal, 2018 ). If a company’s earnings fall short of analysts’ profit projections, investor confidence diminishes, leading to a decline in the company’s stock price ( Kasznik and McNichols, 2002 ; Agha and Rashid, 2023 ). To meet analysts’ earnings forecasts and maximize promised returns, majority shareholders engage in earnings management ( Li and Sun, 2021 ; Hu et al., 2022 ; Dai et al., 2024 ; Duan et al., 2024 ; Wu et al., 2024 ). This satisfies market investors’ earnings expectations and helps maintain or increase the company’s share price. Considering the trade-off between risks and rewards in earnings management, riskier accruals and real earnings management are minimized during the pledging process, while more concealed classification shifting earnings management is preferred.

Considering the analysis presented above, one can propose the following hypotheses:

H3a. The relationship between equity pledges and classification shifting earnings management is positively moderated by analyst attention.

H3b. The moderating influence of analyst attention primarily manifests in the association between equity pledges and downward classification shifting earnings management.

3 Research methodology and data

3.1 variable design, 3.1.1 dependent variable.

In this study, the dependent variable is classified as classification shifting earnings management (UE_CE). The calculation method employed is consistent with the approach outlined in previous research conducted by McVay ( McVay, 2006 ) (Eqs 1 – 3 ).

Upon fitting the model (1) to the pertinent dataset, the unanticipated level is denoted as ε in the model. The growth rate of company assets throughout the operational period is represented by GRA. Sales corresponds to the rate of revenue growth, where if sales are negative, Neg*sale = sale; otherwise, Neg*sale = 0.

Consistent with the methodology proposed by Yang ( Yang et al., 2024 ) this research utilizes the variable |ε| to represent the magnitude of corporate profit manipulation (|UE CE|) when employing specific regression techniques. The directions of manipulation are categorized based on the positive and negative values of |ε|. A positive value of ε denotes an upward direction (UE CE+), while a negative value indicates a downward direction (UE CE-).

3.1.2 Independent variable

The independent variable examined in this study is equity pledge (plgdum). To determine whether the company’s controlling shareholder has pledged equity, dummy variables are employed, following the methodology outlined in the research conducted by Pang et al. ( Pang and Wang, 2020 ). A value of 1 is assigned if an equity pledge exists, while a value of 0 indicates the absence of an equity pledge.

3.1.3 Moderating variables

3.1.3.1 pmc.

To assess the level of competition in the current product market, this study incorporates PMC (PCM) as a moderating variable. The Herfindahl index (HHI) is employed to measure the degree of competition, following the approach outlined in prior research ( Arouri et al., 2021 ). The equation for calculating HHI is presented (Eq. 4 ):

Here, N represents the number of companies operating in the industry. A lower HHI index indicates a higher level of competition, where numerous firms of equal size exist in the industry. In such cases, competition intensifies, and enterprises’ actions are more significantly influenced by one another. The HHI index reaches 0 in an ideal competitive environment, while a value of 1 signifies the presence of a single oligopoly in the industry.

3.1.3.2 Analyst attention

Drawing from the research conducted by Byun ( Byun and Roland, 2022 ), this study incorporates analyst attention as another moderating variable. The number of analysts covering a specific company at time t+1 is represented by the natural logarithm of analyst attention, as expressed in Eq. 5 .

3.1.4 Control variables

This study considers several control variables based on existing research in the literature. The size of the enterprise (size) is measured by taking the natural logarithm of the total assets at the end of the period, increased by 1. The financial leverage (lev) is assessed using the asset-liability ratio. Profitability is evaluated through the return on equity (roe). The company’s growth potential is assessed using the growth rate (gro) of total assets. Ownership concentration is measured by the ownership structure (top1) and the shareholding ratio of the largest shareholder. The independence of the board of directors is evaluated by the proportion of independent directors on the board in the current year (idr). A higher value indicates a higher degree of board independence. Duality (dual) is represented as a binary variable, where 1 indicates that the board chairman also serves as the general manager, while 0 signifies separate roles. Compensation incentive (pay) is calculated as ln (the sum of the top three highest salaries in management) . The industry to which a company belongs is denoted as industry (ind). The variable year (year) indicates the year in which the firm was established. For detailed variable definitions, please refer to Table 1 .

Table 1 . Variable definitions in the study.

3.2 Regression models

To examine hypothesis 1, this study constructs the following regression model in Eq. 6 :

To test hypothesis 2, the following regression model (Eq. 7 ) is utilized:

For hypothesis 3, the regression model is formulated as follows in Eq. 8 :

3.3 Data and sample

3.3.1 sample selection.

This study focuses on China A-share listed companies from 2016 to 2022, and the sample selection process follows the criteria below:

1- Exclusion of companies listed less than 2 years ago, as the calculation of Classification shifting earning management requires a minimum of 2 years of financial data.

2- Exclusion of companies with ST designation due to their financial data not reflecting the normal level of company operations.

3- Exclusion of financial listed companies, as their financial statements differ from those of non-financial enterprises.

4- Winsorize on 1% of continuous variables was carried out.

5- Exclusion of data with missing values.

The data for this study is sourced from the China Stock Market & Accounting Research Database, as well as the annual financial statements of publicly listed companies. The final sample size consists of 12,583 observations, and data analysis is conducted using Stata16.0 software.

3.3.2 Overview of variable characteristics

Table 2 provides an overview of the characteristics of the variables. The mean value of Classification shifting earning management (|UE_CE|) is 0.042 with a standard deviation of 0.045, indicating a significant presence of this practice among firms including energy sectors in China. The variable plgdum, representing equity pledges, has a mean of 0.31 and a standard deviation of 0.462, suggesting variations in the decision of firms to pledge their equity. The VIF values for all variables are less than 10, suggesting the absence of multicollinearity.

Table 2 . Descriptive statistics of variables.

3.3.3 Analysis of correlation

As presented in Table 3 , the correlation coefficient between equity pledges (plgdum) and classification shifting earning management (|UE_CE|) is 0.052, indicating a significant relationship at the 1% level. This finding suggests the potential for conducting regression analysis to further examine this relationship.

Table 3 . Pearson correlation analysis between variables.

4 Empirical findings

4.1 relationship between equity pledges and classification shifting.

The regression analysis presented in Table 4 provides insights into the association between equity pledges and classification shifting. In Column 2, the results without controlling for any variables reveal a statistically significant positive relationship between equity pledges (plgdum) and classification shifting earnings management (|UE_CE|). The coefficient for equity pledges is estimated to be 0.00370, with a significance level of 1% (t-statistic = 4.26). These findings suggest that the practice of classification shifting is influenced by the pledge of corporate equity.

Table 4 . Regression analysis of the relationship between equity pledges and classification shifting earnings management.

After controlling for other variables, the results in Column 3 remain consistent. The coefficient for equity pledges decreases slightly from 0.00370 to 0.00234, but it remains significantly positive at the 1% level (t-statistic = 2.68). This indicates that even after considering other factors, equity pledges continue to support the occurrence of classification shifting earnings management.

In columns 4 and 5, we present the findings regarding the relationship between equity pledges and classification shifting in various directions. In column 4, the coefficient for equity pledges (plgdum) is 0.000838, but it is not statistically significant. However, in column 5, the coefficient for equity pledges (plgdum) is 0.00368, with a significance level of 1% (t-statistic = 2.99). This observation indicates that companies with equity pledges demonstrate a higher propensity to partake in downward classification shifting earnings management (UE_CE-). Therefore, the results strongly support Hypothesis 1.

4.2 Evaluating influence of PMC

The results of the regression analysis, as depicted in Table 5 , provide insights into the association between PMC and its moderating influence on both equity pledges and classification shifting. The table showcases various variables and their corresponding coefficients, along with statistical significance levels.

Table 5 . Regression analysis: the moderating effect of PMC on equity pledges and classification shifting.

The interaction term between equity pledges and PMC (Plgdum*PCM) is of particular interest in understanding the moderating effect. In the third column of Table 5 , the coefficient for Plgdum*PCM, is 0.0165, indicating a significant positive moderation effect at the 1% level (t-statistic = 4.49). These findings indicate that the presence of PMC, strengthens the association between equity pledges and classification shifting.

Further analysis in columns 4 and 5 focuses on the specific effects of equity pledges, PMC, and classification shifting, considering the direction. In the fourth column, the coefficient for Plgdum*PCM in upward classification shifting (UE_CE+) is 0.00355, which is statistically insignificant. Conversely, in the fifth column, the coefficient for Plgdum*PCM is 0.0142 when examining downward classification shifting (UE_CE-). The correlation coefficient for this variable exhibits a statistically significant positive relationship at the 1% level (t-statistic = 3.12), suggesting that the influence of PMC as a moderator is particularly pronounced in the context of equity pledges that involve downward classification shifting (UE_CE-). These findings provide support for Hypothesis 2.

4.3 Analyst attention and equity pledges: classification shifting and competition

Table 6 presents the findings from a regression analysis that investigates the relationship between equity pledges and classification shifting earning management, considering the moderating effect of analyst attention. The table provides information on various variables and their respective coefficients, along with the statistical significance levels.

Table 6 . The moderating effect of analyst attention on the relationship between equity pledges, classification shifting, and PMC: Regression analysis results.

The third column of Table 6 reveals the coefficient of the interaction term between analyst attention and PMC (Plgdum*ANALYST), which is 0.00144. This coefficient is statistically significant at the 5% level (t-statistic = 1.99), indicating that PMC, positively moderates the relationship between equity pledges and classification shifting.

The results for the analysis of the direction of classification shifting earning management are presented in columns 4 and 5 of Table 6 . Specifically, for downward classification shifting (UE_CE-), the coefficient for the interaction term between equity pledges and analyst attention (Plgdum*ANALYST) is 0.00329. This coefficient exhibits a statistically significant positive correlation at the 1% level (t-statistic = 3.21). Conversely, in the case of upward classification shifting, the coefficient for the same interaction term is −0.000196, which is not statistically significant. These findings indicate that the moderating effect of analyst attention primarily influences downward classification shifting earning management. Therefore, Hypothesis 3 is supported.

4.4 Further analysis and robustness testing

4.4.1 the moderating role of liabilities.

This subsection investigates the moderating influence of liabilities on the relationship between equity pledges, PMC, and classification shifting earnings management. Companies burdened with high levels of debt may face amplified operating pressures, heightened scrutiny from stakeholders, and stronger incentives to alter their business strategies in order to bolster core earnings within fiercely competitive product markets. In order to assess potential variations in this relationship, the level of debt is incorporated as a factor in the analysis. The regression results, incorporating debt as an additional variable, are presented in Table 7 .

Table 7 . The relationship between equity pledges, PMC, classification shifting, and liabilities: Regression analysis results.

Notably, the coefficient for the interaction term between debt, PMC, and equity pledges (Plgdum*PCM*lev) is 0.0415, signifying statistical significance at the 5% level (t-statistic = 1.97). This finding suggests that when the level of company debt increases, PMC moderates the relationship between equity pledges and classification shifting earning management. Further examining the relationship, the coefficients for the three interactions of debt, PMC, and equity pledges (Plgdum*PCM*lev) in columns 3 and 4 of Table 7 are −0.0629 and 0.0599, respectively. These coefficients are statistically significant at the 10% (t-statistic = −0.0629) and 5% (t-statistic = 0.0599) levels. These findings suggest that in firms with elevated debt levels, the positive association between equity pledges and downward classification shifting earning management is intensified by the presence of strong product market competition.

The regression analysis findings, as displayed in Table 8 , incorporate liabilities as a moderating factor. This examination investigates the correlation between analyst attention, equity pledges, and classification shifting earnings management.

Table 8 . The moderating effect of liabilities on the relationship between analyst attention, equity pledges, and classification shifting: Regression analysis results.

In column 2 of Table 8 , the coefficient for the interaction term (Plgdum*ANALYST*lev) is 0.00820, which is statistically significant at the 5% level (t-statistic = 2.04). This finding suggests that the moderating effect of PMC, strengthens when the level of firm debt increases. Furthermore, when considering the distinction between upward and downward classification shifting earning management in columns 3 and 4 of Table 8 , the coefficients for the interaction terms (Plgdum*ANALYST*lev) are 0.00902 and 0.00814, respectively. These coefficients are significant at the 10% level (t-statistic = −1.65) only for downward classification shifting earning management. This indicates that the level of debt in a company reinforces the moderating effect of analysts’ attention on the relationship between equity pledges and downward classification shifting earning management.

4.4.2 Propensity score matching test: accounting for Firm characteristics and sample selection

To address the potential influence of firm-specific characteristics on equity pledging decisions and earnings manipulation, a PSM test is conducted in this study. To enhance the credibility of the findings, this analysis takes into account these internal factors, aiming to address potential biases and strengthen the robustness of the results. In the PSM test, firms that have equity pledges (plgdum = 1) are treated as the treatment group, while firms without equity pledges (plgdum = 0) serve as the control group. To mitigate potential endogeneity issues arising from the binary variable (0–1) indicating the presence of equity pledges based on firm characteristics, a logit model is utilized to estimate the propensity scores. The samples with the closest scores are then matched in a 1:1 ratio, and subsequent regression analysis is conducted to address endogeneity concerns.

Figure 1 illustrates the standard deviation of covariates before matching, showing significant deviations in control variables such as company size (size), dual positions (dual), and equity structure (top1). These deviations potentially contribute to endogeneity. However, after matching ( Figure 1 , matched), the deviations in company size (size), dual positions (dual), and equity structure (top1) become minimal. The deviations in these covariates decrease significantly, with most of them converging to zero or within a 10% range, indicating successful matching and passing the smoothness test.

Figure 1 . Standard deviation of covariates before and after matching in propensity score matching analysis.

Figure 2 demonstrates the common support domain after matching, revealing equal distributions in the top and bottom ranges. The majority of corporate samples are successfully matched within this domain, confirming the suitability of the PSM method.

Figure 2 . Common support domain after matching in propensity score matching analysis.

Figures 3A,B present the kernel density plots of the treatment group (firms with equity pledges) and the control group (firms without equity pledges) before and after matching. It can be observed that the distributions of top1 (equity structure) and other fundamental characteristics become similar after matching, indicating effective control of confounding factors.

Figure 3 . Nuclear density plot of covariates (A) before and (B) after matching in propensity score matching analysis.

Following the completion of propensity score matching and regression analysis on the matched samples, the results are presented in Table 9 . The second column of Table 9 reveals a regression coefficient of 0.00371 for equity pledge (plgdum), indicating a statistically significant positive association between equity pledge and classification shifting earnings management (|UE_CE|). These findings provide support for Hypothesis 1.

Table 9 . The relationship between equity pledge and classification shifting earnings management: PSM test results.

Furthermore, Table 9 third and sixth columns examine the moderating effects of PMC and analyst attention. In the third column, the coefficient for the interaction term between equity pledge and PMC (Plgdum*PCM) is 0.0105, significant at the 10% level (t-statistic = 1.65), supporting Hypothesis 2 that PMC positively modifies the relationship between equity pledge and classification shifting earnings management. Similarly, the sixth column reveals that the interaction term between equity pledge and analyst attention (Plgdum*ANALYST) has a coefficient of 0.00241, significant at the 5% level (t-statistic = 2.01). This finding further supports Hypothesis 3, indicating that PMC positively modifies the relationship between equity pledges and classification shifting earnings management.

4.4.3 Variable substitution

To ensure the reliability of the empirical findings in this study, a variable substitution technique is implemented, following the approach described by Liang et al., 2023 . The objective of this technique is to test the robustness of the results. In this research, various control variables are substituted and added to the original model.

Initially, the variable representing the natural logarithm of total assets (size) is replaced with the natural logarithm of operating income (size1) as an alternative measure of the company’s size. Similarly, the return on net assets (roe) is substituted with the return on total assets (roa) to assess profitability. Additionally, the growth rate of total assets (gro) is replaced with the growth rate of operating income (gro1). In terms of equity ownership aggregation, the original variable representing the ownership of the largest shareholder (top1) is replaced with the total ownership of the top 10 shareholders (top10). Additionally, the introduction of control variables for executive compensation incentives and equity incentives aims to account for their impact on the empirical findings. Compensation incentives (PAY2) are computed as the natural logarithm of the sum of the top three highest salaries of management. The results of the empirical regression, including the added and replaced control variables, are presented in Table 10 .

Table 10 . Variable substitution.

Table 10 showcases the relationship between equity pledge and classification shifting earning management, as well as the moderating effects of PMC and analyst attention. Based on the findings in the second column of Table 10 , the regression coefficient is 0.00226, indicating a significant positive correlation between classification shifting (|UE CE|) and equity pledge behavior (plgdum). Therefore, Hypothesis 1 is supported by the empirical evidence. Moreover, the moderating effects of PMC and analyst attention are examined in the third and sixth columns of Table 10 . The coefficient of the interaction term between equity pledge and PMC (Plgdum*PCM) in the third column is statistically significant at the 1% level (t-statistic = 4.84), suggesting a positive moderation effect. This finding confirms Hypothesis 2.

Furthermore, the coefficient of the interaction term between analyst attention and PMC (Plgdum*ANALYST) is 0.00145, significant at the 5% level (t-statistic = 1.99). This result indicates a positive moderation effect of PMC on the relationship between equity pledges and classification shifting earning management, supporting Hypothesis 3.

4.4.4 Replacement model

In order to ensure the robustness of the study, a model replacement method was adopted, following the approach described by Chen et al., 2022 . The original model was replaced with a hybrid OLS model, and the regression results are presented in Table 11 .

Table 11 . Replacement model: Relationship between equity pledge, classification shifting earning management, and moderating effects of PMC and analyst attention.

Table 11 illustrates the results of the model substitution analysis. The relationship between equity pledge and classification shifting earning management is examined after replacing the variables. The second column of Table 11 reveals that the variable “equity pledge” (plgdum) is significant at the 1% level in relation to the variable “classification shifting” (|UE CE|). The regression coefficient is 0.00316 (t-statistic = 3.64), indicating a positive association between classification shifting and firms’ equity pledging behavior. Hence, the empirical findings presented in the second column of Table 11 provide support for Hypothesis 1. Additionally, the third and sixth columns of Table 11 examine the moderating effects of PMC and analyst attention. In the third column, the interaction term between equity pledge and PMC (Plgdum*PMC) exhibits statistical significance at the 1% level (t-statistic = 4.60), indicating a positive moderating effect. This outcome confirms the validity of Hypothesis 2. Additionally, the coefficient of the interaction term between analyst attention and PMC (Plgdum*ANALYST) is 0.00147, significant at the 5% level (t-statistic = 2.02). This result suggests a positive moderating effect of PMC on the relationship between equity pledges and classification shifting earning management, supporting Hypothesis 3.

4.4.5 Grouping test: moderating effects of PMC and analyst attention

To examine the moderating effects of PMC and analyst attention, a grouping test was conducted ( Wang et al., 2022 ; Velthoen et al., 2023 ). The sample firms were divided into two groups based on the annual mean value of PMC. Firms with competition levels above the mean were designated as highly competitive (High-competition), whereas those below the mean were classified as oligopolistic (Low-competition). Similarly, firms with analyst attention levels surpassing the mean were categorized as high attention (High-attention), while those below the mean were labeled as low attention (Low-attention). The results of the regression analysis are displayed in Table 12 .

Table 12 . Grouping test: Moderating effects of PMC and analyst attention on the relationship between equity pledge and classification shifting earning management.

Table 12 provides the findings of the grouping test. The regression coefficients and t-statistics are reported for each variable in the different groups. The coefficient of the equity pledge variable (plgdum) in relation to classification shifting earning management is shown for the high-competition and low-competition groups, as well as for the high-attention and low-attention groups. In the high-competition group (column 2 of Table 12 ), the coefficient of the equity pledge with classification shifting earning management (Plgdum*PCM) is 0.00327 and statistically significant at the 1% level (t-statistic = 2.71). Nevertheless, within the low-competition group (column 3 of Table 12 ), the coefficient for the equity pledge variable is 0.00082 and lacks statistical significance. These findings offer confirmation for Hypothesis 2, suggesting that PMC acts as a positive moderator in the association between equity pledges and classification shifting earning management. As for analyst attention, within the high-attention group (column 3 of Table 12 ), the coefficient for the equity pledge variable pertaining to classification shifting earning management is 0.00282 and exhibits statistical significance at the 5% level (t-statistic = 2.49). In contrast, in the low-attention group (column 4 of Table 12 ), the coefficient of the equity pledge is 0.00198 and significant at the 5% level (t-statistic = 1.51). These findings support Hypothesis 3, indicating that analyst attention positively moderates the association between equity pledges and classification shifting earning management.

5 Conclusion

This study provides insights by examining the moderating influences of PMC and analyst attention on the association between equity pledges and classification shifting earning management, thereby extending the existing literature. To address concerns related to endogeneity and ensure the reliability of the results, we conduct rigorous endogeneity and robustness tests. The regression model is constructed using a comprehensive dataset encompassing Chinese A-share firms over the period from 2016 to 2022. The key findings of this study are summarized as follows:

Firstly, the presence of equity pledges among listed companies in China leads to an increase in classification shifting. In comparison to firms without equity pledges, companies with equity pledges take advantage of information asymmetry to project signals of promising operations. They engage in earning manipulation, albeit avoiding deception, in order to secure additional financing or prevent financial distress caused by significant stock price shocks after receiving pledged funds. Furthermore, the direction of earning management associated with classification shifting resulting from equity pledges is downward, primarily for the purpose of profit smoothing.

Secondly, the relationship between equity pledges and classification shifting earning management is positively moderated by market competition. As PMC intensifies, firms face higher operating pressures and capital requirements. The reduced likelihood of obtaining excess profits and increased difficulty in market regulation result in higher levels of classification shifting earning management in the presence of equity pledges.

Moreover, the impact of analyst attention on the relationship between equity pledges and classification shifting earnings management is of a positive nature. When analysts allocate more attention to a company, they engage in diligent monitoring of its performance and generate more accurate earnings forecasts. As a result, heightened analyst attention is associated with an increased occurrence of classification shifting in earnings management pertaining to equity pledges.

Lastly, highly leveraged firms with equity pledges exhibit higher levels of classification shifting earning management compared to less leveraged firms, particularly in the face of intense market competition and heightened analyst attention. The challenges faced by highly indebted companies in obtaining financing and coping with operational pressures under fierce market competition and scrutiny from analysts contribute to classification shifts to some extent.

Based on the outcomes of this study, it is crucial to approach downward classification shifting earning management, motivated by profit smoothing, with caution. Furthermore, the influence of PMC and analysts should be duly acknowledged when studying classification shifting earning management associated with equity pledges.

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.

Author contributions

RX: Conceptualization, Formal Analysis, Investigation, Methodology, Validation, Visualization, Writing–original draft. JL: Conceptualization, Investigation, Methodology, Project administration, Supervision, Validation, Visualization, Writing–review and editing.

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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Keywords: equity pledge, earnings manipulation through classification shifting, product market competition, analyst attention, leverage heterogeneity, Sustainability

Citation: Xue R and Lu J (2024) The role of product market competition and analyst attention in modulating the link between equity pledges and classification shifting. Front. Energy Res. 12:1385311. doi: 10.3389/fenrg.2024.1385311

Received: 12 February 2024; Accepted: 25 June 2024; Published: 15 July 2024.

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*Correspondence: Jiao Lu, [email protected] , [email protected]

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.