Abstract
Public interest litigation (PIL) is widely recognized as an effective tool for promoting social change and protecting public interests. In response to growing social and environmental challenges, China has significantly developed its PIL system. However, existing research has primarily focused on specific legal aspects, without providing a comprehensive analysis of its overall evolution. This study employs Latent Dirichlet Allocation (LDA), a statistical topic modeling technique, to examine thematic shifts in China’s PIL framework through key legal texts. The findings demonstrate that LDA is a reliable and interpretable method for uncovering topic changes, revealing the sustained significance of issues such as environmental protection, food safety, judicial fairness, and cultural heritage preservation. Based on these evolving themes, the study proposes targeted policy implications, including strengthening regulations, enhancing judicial transparency, promoting corporate responsibility, and preserving cultural heritage. This research contributes to a deeper understanding of the development of China’s PIL system and highlights the value of data-driven approaches in advancing legal studies and informing policymaking.
Introduction
Public interest litigation (PIL) refers to legal action taken to protect and promote the general public's well-being and address societal issues. As a recognized tool for driving social change, PIL is widely used by marginalized or disadvantaged groups to defend their legal rights and interests and foster societal transformation (Kong, 2009). Rapid economic growth has led to improved living standards in China's transition from a planned to a market economy. However, this progress has also brought about numerous collective social issues, such as recurring food safety concerns and environmental pollution. As a result, there has been an increasing focus on the effectiveness of China's public interest litigation system, particularly the development and evolution of its legal framework. This study explores the evolution of China's public interest litigation legal system using Latent Dirichlet Allocation (LDA) topic modelling.
While traditional legal research typically emphasizes theoretical frameworks, this study empirically maps the topic evolution of PIL law through a computational text-mining approach. As Grimmer and Stewart note, this approach is critical when analyzing large-scale textual data, where manual coding or deductive theory testing may fail to capture underlying patterns (Grimmer & Stewart, 2013). By thoroughly examining the evolution of relevant laws and policies, we can comprehensively understand the system’s development. Existing research on China's public interest litigation legal system has primarily focused on specific aspects of the jurisprudence surrounding PIL, with relatively few studies compiling or analyzing the overall legal framework and system. For instance, current studies address whether non-profit legal entities can sue when public interests are infringed upon (Qiang, 2006), the establishment and practice of environmental courts and tribunals in China (Wang, 2010), the role of environmental non-governmental organizations (NGOs) in these suits (Mingde & Fengyuan, 2011), and the establishment of a litigation system for ecological (Jiang et al., 2020) and environmental damages aimed at confirming the position of the government in the protection of environmental public interests (Xie & Xu, 2021).
The studies mentioned above have emerged alongside the development of public interest litigation in China, offering valuable insights into the evolution of the country’s legal system for PIL. Nevertheless, as research on public interest litigation continues to deepen, there is an ongoing need to adopt new research methodologies to enhance the effectiveness of existing legal studies. With this in mind, this study aims to analyze a substantial body of legal documents related to public interest litigation in China using LDA topic modeling techniques. This approach aims to reveal the evolving topics, trends, and challenges within China’s legal framework for PIL. The findings of this study will contribute to a comprehensive understanding of the development and effectiveness of public interest litigation in China. Furthermore, this study will demonstrate the value of the LDA topic modeling technique in examining the legal system for PIL, encouraging its broader use in research, policy development, and lawmaking processes in related fields. The study will also highlight areas that require further attention or reform to strengthen and advance the public interest litigation system.
Literature Review
Public interest litigation (PIL) has been successfully utilized globally to promote social justice and the rule of law, advocating for civil rights and environmental protection while striving to eradicate inequality and discrimination. The establishment of China's public interest litigation framework can be traced back to enacting the Consumer Rights and Interests Protection Law in 1993, followed by several laws and decrees that have gradually expanded the scope of PIL. Over the past three decades, China's legal system for PIL has undergone significant changes, evolving from spontaneous actions to institutionalization and case-by-case handling to social mobilization (Fu & Cullen, 2009). This framework has been crucial in addressing important legal and social issues arising from reforms and development. PIL is often considered a significant legal breakthrough in promoting environmental law enforcement and fostering court-centered environmental campaigns (Gao, 2018). Zhang and Mayer (2017) documented the rapid growth of environmental PIL in China, resulting in court decisions favoring plaintiffs. However, challenges and institutional flaws persist in implementing PIL within China's legal system. Recent studies suggest that while the volume of PIL cases grows, deeper topic inconsistencies and jurisdictional disparities remain prevalent across regions, undermining the overall policy coherence (Tang et al., 2024; Guo, 2024). These studies focus on case quantity metrics and overlook latent discursive patterns in judicial texts—an issue addressed by our LDA-driven analysis of legal documents, which decodes semantic evolution. Gao (2018) argues that the Chinese PIL system presents more problems than it solves, citing long-standing legal and political barriers and procedural design issues. This critique aligns with recent research that emphasizes the need for improvements in algorithmic topic modeling for legal policy interpretation (Liu, 2025).
Additionally, the existing legal provisions regarding PIL are complex and unclear, leading to practical disagreements. Addressing these institutional deficiencies and challenges requires a thorough understanding and exploration of PIL's institutional framework, focus areas, and scope. Extensive research has been conducted by scholars and research institutions on the evolution and development of China's PIL legal system. For example, Xie and Xu (2022) analyzed 570 court cases and concluded that public prosecutors form the cornerstone of the public interest litigation system, achieving maximum efficiency in winning cases. Our temporal topic modeling extends this finding by revealing prosecutor-driven topics. While Xie and Xu’s qualitative analysis effectively demonstrates prosecutorial dominance in PIL outcomes, their manual coding approach inherently limits scalability, especially in tracking macro-level topic shifts across many environmental PIL cases. These research studies provide valuable insights into the development and transformation of China’s PIL legal system. However, there is still a need to fill the existing research gaps and further investigate the practical efficacy and impact of judicial interpretations on PIL.
Topic modeling, one of the most potent techniques in text mining, allows for generalizing textual data based on latent variables that correspond to underlying topics or topics (AlSumait et al., 2009). Various methods for topic modeling exist, with Latent Dirichlet Allocation (LDA) being one of the most widely adopted approaches (Jelodar et al., 2019). The LDA topic model is an unsupervised learning method (Guo et al., 2021) that automatically generates topics in a text corpus and assigns words from the corpus to these topics. However, not all estimated topics have equal importance, and not all topics correspond precisely to the actual topics of the domain. Human intervention is necessary to identify meaningful topics.
Due to its multiple advantages, LDA topic modeling has gained popularity for various applications ranging from document modeling to computer vision (Teh et al., 2007). Furthermore, LDA has been extensively applied in policy text analysis. For instance, Yue et al. (2021) utilized the LDA model to recognize technological topics contained within coal-related policies and analyze the policies’ significance toward those technological topics. Prehanto et al. (2020) classified public comments on government policies related to Twitter using the LDA model, revealing that the most discussed topics concerned the government’s efforts to address inequality and improve sectors such as education, healthcare, employment, and infrastructure. Recent work by Wang and Zhang has also applied STM and dynamic topic modeling in legal corpus analysis, showing that topic saliency shifts with changes in statutory priorities and political narratives, particularly in areas such as AI regulation and environmental law (Wang et al., 2025). Therefore, when studying the legal system of PIL, applying the LDA topic model can effectively analyze numerous legal documents to uncover latent topics and evolutionary trends. By employing the LDA topic model, researchers can successfully identify and compare PIL topics across different domains and periods, unveiling the changes and development of the PIL system. Of course, it is essential to acknowledge that LDA-based probabilities are inherently limited in capturing the full nuances of legal texts. This necessitates ongoing algorithmic refinement and larger datasets or cases.
To conclude, studying the evolution and development of China’s PIL legal system is essential. While existing academic studies have explored the institutional framework of PIL (Fu & Cullen, 2009; Gao, 2018), there are critical gaps, particularly in tracking the dynamic evolution of legal texts. Applying the LDA topic model for corpus-driven pattern detection on a large sample of legal documents can provide insights into the underlying themes and evolutionary trends of public interest litigation, and provide support and reference for the reform and development of China’s public interest litigation legal system. The model's ability to reveal the evolution of textual themes complements traditional theoretical analyses and provides empirical validation of Zhang and Mayer’s observation on judicial prioritization dynamics (Zhang & Mayer, 2017). Future research efforts should fill existing gaps by exploring the topic evolution of PIL and its practical effects, examining how China's governance model has shaped PIL topic evolutions and conducting comparative cross-jurisdictional studies.
Methodology
This study utilizes the LDA topic modeling approach to analyze the development of China’s legal system for public interest litigation. The study proposes a multidimensional research method that combines natural language processing (NLP) and information retrieval techniques to study the evolution of the public interest litigation system. By employing LDA tools, hidden topic information within large-scale document collections can be revealed (Andrzejewski & Zhu, 2009), enabling more meaningful extraction of topics (Albalawi et al., 2020), not constrained by text size. The importance of topics in policy documents can be reflected by calculating the probability of each topic appearing in a document, thus providing an in-depth evaluation of the topic and probability ratios in policy documents and shedding light on the trends in policy development and optimization.
The specific data analysis process consists of the following steps: Firstly, preprocessing the policy documents. Python is employed to batch download and process China’s legal and policy-related documents on public interest litigation. By removing noisy data that does not match the topic or is unsuitable for modeling and utilizing the Jieba Chinese word segmentation tool, the raw legal and policy documents are segmented to derive word segmentation results and part-of-speech information. Stop word lists and custom dictionaries related to public interest litigation in China are employed to clean further and optimize the policy documents, resulting in a dataset that aligns with the research purpose.
Secondly, keyword analysis is conducted. Firstly, the word cloud library in Python calculates the word frequency in the concatenated string derived from the previous preprocessed text, generating a word cloud visual representation. Simultaneously, a specified number of high-frequency words and their frequencies are displayed. An understanding of the critical areas and focal points of China's public interest litigation legal system can be gained by examining the high-frequency words and their frequencies. The high-frequency words are used as nodes to construct a co-linear network of keywords, with the attributes of elements in the image set based on the node word frequency attributes, thus highlighting the relationships between different keywords and revealing the interconnections among key areas of China’s public interest litigation system.
Thirdly, the LDA model is employed to extract topics. The optimal number of topics is initially determined through topic perplexity and visualization. A range of 2 to 16 topics is defined, and a topic iteration cycle is executed. An LDA model is constructed for each number of topics, and the perplexity of different topics is calculated. The optimal range of the number of topics is identified by examining the perplexity scores and variations. Additionally, the pyLDAvis visualization tool is utilized to visualize the topics generated by the LDA model, ultimately determining the optimal number of topics.
Subsequently, the LDA topic modeling incorporates the determined number of topics, and the desired topics and a specified number of feature words are outputted. Analyzing the feature words associated with each topic gives a comprehensive understanding of the content covered by different topics. Finally, the Chinese public interest litigation laws and policies are segmented based on time, enabling the calculation of the topic intensity for each stage and presenting the hot topics in renewable energy policy during different periods.
For this study, a selection of legal normative texts from Peking University’s Fabao Policy Database about central and local regulations under the term “China’s public interest litigation” was obtained as data samples. Among the collected materials, there are 81 central regulations and 188 local regulations, covering various normative documents from 2006 to 2023. After excluding non-text files and documents irrelevant to the subject matter, the final sample consists of 267 documents. The LDA model’s inductive nature allows for theory-agnostic exploration of textual patterns, complementing (rather than replacing) doctrinal analyses. This approach allows for the identification of empirically based themes that challenge or refine existing theoretical assumptions.
Data Analysis Result and Discussion
Policy Keyword Analysis
High-Frequency Vocabulary Analysis
This study first utilizes the Python word cloud library to process the preprocessed Chinese public interest litigation legal texts, selects high-frequency words to generate word cloud images, and outputs the top 20 high-frequency nouns, as detailed in Table 1.
High-Frequency Words in Policy Texts (Top 20).
Based on the word cloud results, several key points exist. Firstly, “Public Interest Litigation” is a prominent topic throughout the system, highlighting its legislative purpose of serving the “Public Interest.” Secondly, high-frequency terms such as “Ecological Environment,”“Social,”“Problems,” and “Environment” indicate that the Chinese public interest litigation system focuses on environmental and social concerns, including the protection of natural resources and the environment, as well as the safeguarding of public interests and the rights of relevant stakeholders.
Thirdly, the frequent appearance of terms like “Prosecutor’s Office,”“Procuratorial Recommendations,” and "Prosecution" illustrates the important but complex role of procuratorial organs in the reform and implementation of the public interest litigation system in China. While these terms suggest a significant involvement of procuratorial bodies, it is important to recognize that the effectiveness of their role varies depending on local implementation and the alignment of judicial and administrative practices. Fourthly, the words “Work,”“Cases,” and “Illegal” emphasize the case-oriented nature of the legislation, with the establishment and development of the public interest litigation system being driven by the discovery and rectification of the limitations of existing laws through the emergence and resolution of cases.
Additionally, the high frequency of terms such as “Administrative Organs” suggests that the Chinese public interest litigation system encompasses the actions of administrative departments and institutions. These organs can act as law enforcers while also being subject to supervision and legitimacy review within the public interest litigation system. Lastly, the repeated use of the phrase “By Law” underscores the fundamental principles and adherence to the rule of law in public interest litigation, building upon a foundation of multiple legal frameworks. It represents an essential requirement for the operation of public interest litigation and the fundamental source of its legitimacy and rationality.
Keyword Co-Occurrence Network Analysis
The analysis of high-frequency vocabulary mentioned above provides insights into the frequent occurrence of keywords in policy documents. We further conducted keyword co-occurrence network analysis to explore the correlation and co-occurrence patterns among these keywords. The results of this analysis offer a visual representation of the centrality and relevance of the keywords.
Building upon data preprocessing, we utilized the bag-of-words model to convert the text data into a vector representation. Subsequently, the keyword co-occurrence network was constructed based on the relationships between the keywords. In this network, high-frequency feature words were selected as nodes, and words irrelevant to the domain of policy or legal norm adjustments were removed based on semantic considerations. The weight of the edges was determined by calculating the co-occurrence probability between two nodes, reflecting the number of texts that simultaneously contained these two nodes. In the keyword co-occurrence network, the size of each node represents the frequency of the keyword in the co-occurrence matrix, while the shade of the node indicates its importance. The thickness of the connecting lines denotes the intensity of co-occurrence between keywords. Specific results are visualized in Fig.1 below.
Keywords co-occurrence network.
In the field of public interest litigation in China, the results of the co-occurrence network analysis reveal a series of meaningful patterns and connections. Firstly, the core concept of “Public Interest Litigation” stands out as the most critical node, displaying the deepest color and demonstrating a high likelihood of co-occurrence with other keywords in the network structure. This result indicates that China’s public interest litigation system is a multi-level and multi-dimensional concept that requires the collective efforts of various fields and authorities. As a unique legal mechanism, public interest litigation effectively addresses issues in diverse areas of the environment and society, playing a crucial role in protecting public interests and upholding social justice. It highlights PIL’s broad scope and adaptability, reflecting its capacity to respond to evolving social and legal challenges, from consumer rights to environmental protection.
Secondly, in addition to the topic of “Public Interest Litigation” the keyword “by law” holds utmost significance, closely associating with both “Public Interest Litigation” and other key terms. Supporting “by law” ensures the legality and fairness of public interest litigation. This term underscores the importance of a legally structured framework that governs PIL and enforces its procedures. It aligns with the principle that public interest litigation must be carried out within the boundaries set by national legislation, ensuring legal accountability. Implementation relies on adherence to the procedures and requirements stipulated by the law, ensuring justice, fairness, and legality. Furthermore, “by law” harmonizes the potential conflicts between legislation and law enforcement, providing valuable guidance for developing and reforming China's public interest litigation system while promoting cooperation and supervision among different authorities. This interaction between law and enforcement helps mitigate the risk of arbitrary or selective application of the law, ensuring a fair and transparent PIL process.
Thirdly, as an essential area within public interest litigation, the “Ecology and Environment” is less prominent in legal texts than the previous keywords but exhibits noticeable advantages over other terms. The emergence of China’s public interest litigation system coincides with an increasing awareness of environmental protection. Public interest litigation offers a significant legal avenue for environmental protection, facilitating the safeguarding and restoration of environmental rights through means such as defending rights, imposing sanctions, and mediation. These legal instruments, especially sanctions, are crucial for compelling compliance with environmental laws and holding both public and private entities accountable for their environmental impact. This method effectively addresses the arduous challenges encountered in environmental rights protection, but the system’s ability to enforce widespread ecological justice is still in progress. Despite the existing difficulties and shortcomings during the implementation phase, progress is being made, although it may be uneven across regions and sectors. The continued development of PIL in this area is significant, as it aligns with China's long-term environmental goals and the increasing recognition of ecological issues as central to public welfare. However, further research and monitoring are needed to assess how effectively these goals are being realized and to identify areas where improvements are still required.
Fourthly, keywords closely associated with public interest litigation encompass “prosecution,”“Duties,”“Oversight,”“Remediation,”“Specialized,” and “Activities.” They exhibit substantial connectivity with public interest litigation, underscoring the crucial roles played by regulatory bodies, procuratorial organizations, and associated responsibilities in ensuring successful implementation. The operation of China’s public interest litigation system is contingent upon the participation of law enforcement authorities and is supported by laws and regulations. Procuratorial departments assume pivotal responsibilities in public interest litigation, and the smooth and orderly implementation of the system requires adequate supervision and guidance from these entities. Prosecutorial oversight ensures that PIL serves its function of protecting public rights and preventing abuses of the legal system, acting as a safeguard against the misuse of PIL by private interests. Further analysis reveals a strong connection between the term “Specialized” and words such as “Activities,”“Oversight,” and “Prosecution” indicating that special activities serve as a common mechanism driving public interest litigation, necessitating support from supervision and procuratorial bodies. Moreover, the significant relationship between “Pollution of the Environment” and “Ecology and Environment” as well as “Prosecution” and “Duties,” highlights the influential role played by prosecutorial public interest litigation in both environmental protection and the fulfilment of supervisory duties. These links reflect how prosecutorial entities not only hold environmental violators accountable but also play an active role in shaping policies and frameworks that enhance environmental protection and sustainability.
Lastly, terms such as “Typical Cases,”“Incidental civil,” and “Adocacy” exhibit relatively more minor nodes and lighter colors within the network yet still maintain a connection with public interest litigation. The development of public interest litigation is grounded in filing and adjudicating public interest cases, gradually expanding the jurisdictional scope through establishing exemplary cases. These typical cases serve as precedents, reinforcing the legitimacy and importance of PIL in resolving public interest disputes, and providing a reference for future cases and judicial decisions. These terms also provide valuable models and support for rectifying infringements on public interests. Notably, public interest litigation's remediation of legal violations is accompanied by a promotional effect that enhances public legal awareness while concurrently rectifying existing limitations and deficiencies within the legal framework. The advocacy associated with PIL also plays a crucial role in educating the public about legal rights and fostering a culture of legal awareness and responsibility.
In summary, the analyses above disclose the connections and importance of key concepts within China's public interest litigation field. Public interest litigation, as the core concept, intertwines closely with elements such as “by law,”“Ecology and Environment,”“Oversight,”“Prosecution,” and “Remediation.” These analyses offer valuable in-depth insights into comprehending the public interest litigation system. By establishing a complex network, the public interest litigation system plays a pivotal role in promoting social welfare’s continuous development and progress, ultimately safeguarding public interests and upholding social justice. These findings highlight how PIL operates as a legal mechanism and a dynamic tool that responds to societal needs, shaping legal reforms, public policies, and societal values.
Topic Clustering Results
Determine the Optimal Number of Topics
In this study, we apply the topic perplexity and visualization methods to select the optimal number of topics. In determining the optimal number of topics, we pre-set the maximum number of topics to 16 and compared the model fitting effect by calculating the logarithmic perplexity of the topics after the LDA cycle modeling. The detailed results are shown in Figure 2 below. Generally speaking, as the number of topics increases, the perplexity will gradually decrease. However, when the number of topics becomes excessively large, the model may begin to overfit the data, capturing noise rather than meaningful patterns. On the other hand, selecting too few topics may lead to underfitting, where the model fails to capture important nuances in the data. Striking the right balance between these two extremes is crucial for obtaining reliable and interpretable topics.
Topic perplexity.
According to the results of the topic confusion degree, when the number of topics exceeds 6, the rate of decrease in the confusion degree slows down, indicating diminishing returns in terms of model improvement. This suggests that adding more topics beyond six does not substantially enhance the model's ability to distinguish between topics, so we should choose the number of topics greater than or equal to 6 as the optimal number. Since too many topics may cause the overfitting problem, we adopt the visualization method of gradually increasing the number of topics. Figure 3 demonstrates that the distribution of topics remains well-separated when the number of topics is set to 6. Although some topics start to overlap, the overlap area is small and within the acceptable range, which is unlikely to impact the results of topic clustering significantly. Therefore, we chose six as the optimal number of topics.
Topic visualization.
Analyzing Topic Content
After analyzing the Chinese public interest litigation legal text corpus with high-frequency words and co-occurrence networks, we use the LDA topic modeling method for topic training and inference to discover potential hidden topics. The detailed results can be seen in Table 2.
Distribution of Topics in Renewable Energy Policies.
The results of topic clustering indicate that texts concerning China's legal system for public interest litigation primarily revolve around the following major topics:
Topic 0: This topic focuses on the legal framework for food safety regulation, sales, and business management. Food safety is a crucial aspect closely tied to public health and safety. Introducing public interest litigation (PIL) can enhance the enforcement and regulation of food safety standards, safeguard consumer rights and interests, and mitigate food safety risks. Through PIL, food companies can be held accountable for their legal responsibilities and encouraged to bolster their food safety management and self-discipline, thereby enhancing the quality and safety of the entire food industry.
Topic 1: This topic pertains to the legal system governing court trial procedures, the parties' rights and responsibilities, and the evidence's examination. Using legal documents such as the Civil Procedure Law of the People's Republic of China and the Law of the People's Republic of China on Public Interest Litigation, the fundamental principles of public interest litigation, along with the rights and responsibilities of the parties, have been elucidated. It ensures procedural fairness and impartiality in court trials, safeguarding the legitimate rights and interests of parties engaged in public interest litigation and offering legal protection to fulfil their obligations effectively.
Topic 2: This topic centres around the legal framework for ecological environmental protection, compensation for ecological damages, and the obligations of supervisory authorities. The Law of the People's Republic of China on Environmental Protection regulates the basic principles of environmental preservation, defines responsible parties and controls pollutant emissions, and includes specific provisions for compensation relating to ecological damages, prioritising the legal system for ecological environmental protection aids in safeguarding the legitimate rights and interests of the ecological environment and promoting sustainable ecological development. Concentrating on the legal system for compensation in cases of ecological damage nurtures the protection of the rights and interests of the impacted ecological environment, encourages compensation for rights violations, and facilitates the restoration of damaged ecological systems.
Topic 3: This topic concerns the legal system for safeguarding personal rights and interests, guaranteeing personal information security, and protecting the rights and interests of disabled individuals. Public interest litigation serves the purpose of protecting the public’s interests and society's overall welfare. Prioritizing the protection of personal rights and interests, personal information security, and the rights and interests of disabled individuals guarantees the safeguarding of legitimate rights and interests, furthering social equity and justice.
Topic 4: This topic revolves around the legal system of corporate responsibility, environmental pollution control, and land preservation. Public interest litigation intends to safeguard the public’s and society's rights and interests. By focusing on cases related to corporate liability, environmental pollution control, and land preservation, public health and interests can be protected, and adherence to legal responsibilities by corporations can be ensured.
Topic 5: This topic deals with the legal system relating to the protection of cultural heritage, the establishment of protected areas for cultural relics and the protection of monumental facilities. Public interest litigation allows for the use of legal means to protect valuable cultural heritage resources, such as historic sites, ancient buildings and cultural relics, and to ensure their proper protection and continuation. These laws and policies are of great significance for realizing social equity and sustainable development and protecting the country’s historical and cultural heritage.
These topic content analyses cover pivotal aspects of the development and progression of China's public interest litigation system, spanning food safety, court trial procedures, ecological and environmental protection, personal rights and interests, corporate responsibility, and cultural heritage preservation. They underscore the significance of public interest litigation and its role across different domains.
Analyzing the Evolution of Topic Intensity
The above analysis concludes that public interest litigation is essential in safeguarding public interests and protecting citizens’ rights and interests. Next, this study will use visualization techniques to further explore the evolution of legal topics of public interest litigation in China from 2006 to 2023. We will categorize the policy texts and topics according to different time windows and create heat maps of the topics under different time windows, as detailed in Figure 4 below. By analyzing the changes in the intensity of the topics in the heat maps, we will highlight the evolving priorities and concerns of China’s public interest litigation system. The results of these analyses can inform the development of the legal framework and help address emerging challenges.
Topic intensity by time window.
The heat map analysis reveals the following key findings: From 2006 to 2012, significant attention was given to Topic 1 in China’s public interest litigation (PIL) laws and policies. This emphasis reflects an initial focus on procedural and court impartiality within the PIL system. During this period, the development of China’s PIL legal framework prioritized strengthening and improving the judicial process to ensure due process and procedural rights for all litigants. This phase also coincided with China’s broader judicial reforms, which aimed to enhance the transparency and impartiality of the judicial system, marking a critical milestone in establishing a standardized institutional framework for PIL in China.
From 2013 to 2014, the intensity of Topic 1 declined, while Topic 0, related to food safety regulations, increased. This shift suggests that food safety issues gained public attention and became a subject of litigation. The intensifying public concern over food safety, particularly after scandals like the 2008 melamine milk scandal and the 2013 rat meat scandal, led to growing demands for stronger legal mechanisms to protect consumer rights. As the PIL system became more formalized, the increasing prominence of Topic 0 reflects policymakers’ responses to the public's demand for stringent regulatory measures to safeguard food safety and quality. It indicates that the government recognized the need for robust regulatory mechanisms to protect consumer rights and food safety, especially following high-profile cases that exposed regulatory failures.
Between 2015 and 2017, there was a notable uptick in interest regarding Topic 2, which pertains to environmental protection. Similarly, interest in Topic 1 also resurged. The rise of Topic 2 corresponds with the 2015 amendment to the Environmental Protection Law, which granted citizens expanded rights to bring environmental lawsuits, reflecting a more proactive stance on ecological preservation. The prominence of Topic 2 indicates a growing awareness of the importance of safeguarding the environment, tackling pollution, and mitigating environmental harm. This period also saw an increased recognition of the connection between economic growth, industrialization, and environmental degradation, prompting more robust legal actions. The revival of Topic 1 underscores the continued commitment to improving court procedures to ensure fairness and impartiality throughout the judicial process. This period exemplifies an increased recognition within China's PIL system of the need to address environmental concerns while strengthening the legal framework governing judicial governance.
The focus on Topic 2 peaked from 2018 to 2020, with Topic 0 also experiencing a modest rise in attention. The sustained emphasis on Topic 2 demonstrates China's unwavering dedication to environmental protection and sustainable development within the PIL system. This focus aligns with China's drive for ecological civilization, underscored by the government's commitment to addressing pressing environmental challenges exacerbated by rapid industrialization and urbanization. Simultaneously, the slight increase in attention to Topic 0 underscores ongoing concerns about food safety, coupled with efforts to establish more robust regulatory mechanisms. The steady focus on food safety indicates the enduring relevance of safeguarding public health amid a growing consumer culture and industrial expansion. The simultaneous emphasis on environmental protection and food safety underscores the evolving nature of China's PIL system, which now encompasses a broader range of social public interest issues and citizen health.
From 2021 to 2023, there was a diversification of focus to encompass issues related to the environment, individuals, businesses, and culture. While the focus on environmental protection (Topic 2) remains, broader topics have begun to emerge. Topic 3, dedicated to individual rights, gradually gained importance, reflecting a heightened concern for personal rights and the protection of personal information. This shift reflects the growing recognition of personal privacy in the digital age, especially with drafting the Personal Information Protection Law in 2020. Topic 4, covering corporate responsibility and pollution control, indicates a growing interest in corporate accountability and the imperative to address environmental pollution resulting from industrial activities. This trend reflects heightened scrutiny of corporate practices and increasing public demand for corporate social responsibility, particularly following environmental scandals involving major corporations. Topic 5 revolves around cultural heritage protection, emphasizing the significance of preserving and safeguarding China’s rich cultural heritage, particularly in light of accelerated urbanization and the threats posed by rapid construction projects to historical sites.
The diverse topics within PIL during this period mirror Chinese society’s evolving challenges and concerns. They reflect a broader recognition of balancing economic development with environmental sustainability, individual rights, corporate responsibility, and cultural preservation. This trend signals the increasing maturity of China’s PIL legal framework, aligning with evolving social values and underscoring the intrinsic relationship between the legal framework and societal well-being.
The evolution of legal topics in PIL in China reflects the dynamic nature of social priorities and the responsive development of the legal system. An analysis of the intensity of these topics shows that PIL has gradually expanded from focusing on developing court proceedings to incorporating key issues such as food safety, environmental protection, individual rights, corporate responsibility, and cultural heritage protection. These shifts exemplify the responsiveness of China’s legal framework to the changing needs and challenges of its society, with an increasing focus on public welfare and the promotion of sustainable development. These changes underscore the adaptability of China’s legal framework and its ability to respond to new challenges related to public welfare. The evolving legal topics highlight the government's commitment to protecting citizens’ rights and interests while promoting sustainable development.
Conclusions and Policy Implications
Using the LDA topic modeling method, this study comprehensively analyzes the developmental evolution of China's public interest litigation (PIL) system, exploring the topic changes across different periods. The research findings demonstrate that the LDA topic modeling approach is highly reliable and interpretable for conducting such an analysis. Through this approach, we were able to accurately identify the key areas of public concern during different periods, revealing the topic importance and associative relationships within the relevant legal and policy texts. The results also highlight the evolving topics of China’s PIL system and their significance over time. Environmental protection, food safety, and judicial procedures consistently emerge as essential topics within China’s PIL framework.
Furthermore, as China undergoes economic and social development, the topics within the country’s PIL system have increasingly diversified. Public interest litigation now encompasses protecting personal rights and interests and preserving historical relics. Observing these patterns of thematic evolution gives us insights into the focal points of China’s PIL system at different times and the policy and legal responses to societal concerns. Notably, according to the 2023 Report of the Supreme People's Procuratorate of the People’s Republic of China on Procuratorial Work on Ecological Environment and Resource Protection, 395,000 cases of PIL in the field of ecological environment and resource protection were filed between 2018 and 2022, with an average annual increase of 12.5%, demonstrating its concrete social effectiveness. The evolving nature of the PIL system serves as a crucial foundation and reference for developing the rule of law in China. This trajectory reflects the Chinese characteristics of “social governance through law” where Party leadership and judicial activism work together to address emerging social contradictions. Based on our findings, we propose the following policy implications:
In conclusion, by integrating the LDA topic modeling methodology, the government and relevant authorities can better understand the development trends and issues within China’s PIL system. Our findings validate the initial research goal of decoding potential topic shifts in the legal texts of PIL while highlighting the orientation of policies in different legislative periods and the legislative guidelines needed for local policymaking at the central level. Moreover, for policymakers in local governments or lower-level authorities to formulate appropriate policy measures that provide better judicial protection and social services to the public—and to promote the progress and development of Chinese society—they need to incorporate the insights provided by data on the evolution of different themes, in addition to the development status of their region. The dominance of environmental protection underscores the urgency of Policy Implication 1, while the emergence of cultural heritage justifies the targeted interventions outlined in Policy Implication 4.
Footnotes
Acknowledgements
I would like to thank all the cited literature and studies that provided the theoretical and empirical basis for my project.
Ethical Considerations
This study employed LDA topic modeling to analyze publicly accessible legal texts. As no human subjects were involved, ethical approval was not required.
Informed Consent
As the study focused on publicly available legal texts and did not engage any human subjects, the acquisition of informed consent was deemed unnecessary.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.