Mapping the Landscape of the Literature on Environmental, Social, Governance Disclosure and Firm Value: A Bibliometric Analysis and Systematic Review

Abstract

Increased interest in sustainability and related issues has led to the development of disclosed corporate information on environmental, social, and governance (ESG) issues. Additionally, questions have arisen about whether these disclosures affect the firm’s value. Therefore, we conducted a bibliometric analysis coupled with a systematic literature review (SLR) of the current literature in the Scopus database from 2001 to 2023. We utilized VOS viewer, Site Space, and R Studio tools for this analysis. Our findings indicate that the relationship between ESG disclosures and the firm’s value has different effects and that disclosure impacts through various channels, such as increasing stakeholder trust. Moreover, the keyword analysis results before and after 2015 demonstrate significant advancement in the utilization of a theoretical foundation in the literature. Furthermore, China (Country), “Universidad de Salamanca” (University), “Uyar, Ali and García-Sánchez, Isabel-María” (Authors), and “Sustainability” and “Corporate Social Responsibility and Environmental Management” (Journals) were the most contributing and influential in this field. On the other hand, the results revealed six thematic clusters: society, sustainable development, ESG, organization, innovation, and stakeholders. We found promising research paths and emerging themes through content analysis of these clusters, such as sustainability assurance, green innovation, and sustainable development goals (SDGs). This review concludes by providing a roadmap that includes emerging lines of research that can be explored in depth in future studies to promote better and more comprehensive integration to achieve sustainability and maximize firm value.

1. Introduction

Companies have integrated ESG practices into their operations due to rapid changes in economic development, including the development of investment strategies and decision-making processes. This integration has led to an increase in the implementation of ESG disclosure. Several factors have contributed to an increased interest in disclosing firms’ ESG practices, including the UN’s 2030 Sustainable Development Goals, international agreements such as the Paris Agreement, societal and media pressures, and corporate social operations [1]. Therefore, increasing ESG practices may contribute to alleviating economic and societal pressures, which has attracted a lot of attention from various parties, including academics, regulators, and economic experts [2]. As a result, corporate ESG investment is essential for a company’s growth because it facilitates relationships with all stakeholders. Thus, these companies contribute to social welfare and mitigate climate change risks. The primary goal of companies is to maximize shareholders’ profits, but they also strive to achieve other objectives, such as social responsibility and benefiting society as a whole. However, there is still skepticism on the part of some researchers and academics about moving away from the perspective and goal of maximizing the value of companies [3]. For example, Meng and Wang [4] indicate that it takes years for companies to practice ESG activities to improve their reputation and enhance their competitive position. It is important to note that the literature has shown that investing in ESG activities contributes to maximizing profits [5], promoting social investment [6], improving the company’s reputation [7], and working to mitigate environmental risks and pollution [8].

There has been increasing interest from academic researchers in the role of a company’s investment in ESG and its impact on firm value in light of the growing interest shown by investors and regulators. Despite this, there is division and disagreement about the extent to which ESG disclosure affects a firm’s value [1]. For example, Ademi and Klungseth, Aydoğmuş et al., Tang et al., and Li, Y [9,10,11,12] show a positive relationship. At the same time, Duque-Grisales and Aguilera-Caracuel [13] show a negative impact. On the other hand, Garcia-Castro et al. [14] indicate no effect. In judging the relationship between ESG practices and firms’ performance, these findings are consistent with conflicting and incompatible theoretical foundations such as shareholder primacy theory, stakeholder theory, and agency theory. In this regard, shareholder primacy theory assumes that there is only one goal for companies, which is to maximize profits and the interests of shareholders without regard to achieving a balance with the interests of society [15]. In contrast, stakeholder theory assumes the opposite of shareholder primacy theory, given that there are multiple parties for which companies are responsible for achieving their interests, including society [15,16]. This theory emphasizes the necessity of taking into account the interests of society in parallel with achieving the interests of shareholders. Regarding agency theory, it indicates that company managers may seek to promote their personal interests by engaging in ESG activities, given that shareholders cannot easily monitor such behavior [17]. As investors and regulators continue to be interested in understanding how ESG disclosure impacts a firm’s value, a comprehensive literature review is still needed, along with identifying research gaps and suggesting future research directions. In this regard, we conducted a comprehensive investigation using extensive keywords and retrieved literature from Scopus, as it is the largest database and includes studies and results accepted by academics [18,19,20]. This review expands to include an investigation of 4,084 comprehensive studies on all aspects of the relationship between ESG disclosure and a firm’s value, ensuring that the limitations of the previous review literature will be covered. For example, Bartolacci et al. [21] investigated the literature that discusses the sustainability of small and medium enterprises and financial performance. Using the Web of Science (WoS) database and only 62 studies covering the period between 1999 and 2018 and using specific keywords (SME* AND sustainab* OR responsib* AND financial AND performance. Huang [22] conducted a traditional review discussing ESG disclosure and company value using literature published in “The Journal of British Accounting Review” published before 2017. Meanwhile, Ref [23] focused on investigating the relationship between ESG performance and the financial performance of companies by conducting a meta-analysis of 21 data retrieved from the WoS database. Widyawati [24] provided a systematic review of the literature indexed in the WoS (SSCI) of the pre-April 2017 literature to discuss socially responsible investing. Therefore, the novelty of this review is that it includes two aspects of analysis: bibliometric analysis and a systematic review of recent literature. This ensures the provision of a research and theoretical basis that explains how to maximize the value of the company through the ESG lens.

This review aims to demonstrate the most important countries, journals, and influential authors, as well as the chronological development of publications in this field. Additionally, it systematically analyzes the topics, which facilitates the provision of a clear and systematic roadmap for future studies. In particular, this study seeks to answer the following questions:

RQ1: What is the chronological development of publications on this topic?

RQ2: Which countries, journals, and authors have had the most impact in this domain?

RQ3: What is the intellectual structure of the recent literature and the emerging aspects?

RQ4: What are the most keywords used in this field?

RQ5: What are the key research themes in this field?

RQ6: What are the directions for future research?

Our review contributes to the literature related to corporate investment in sustainability issues and sustainable financing through a deep analysis of the literature related to ESG disclosure and firm value. It also identifies the issues discussed by the authors and evaluates their contributions to this topic. This review makes substantial contributions to this field. Firstly, it adds to the existing literature on ESG disclosure, highlighting its importance. Secondly, it offers insights by examining authors’ keywords, offering a holistic view of the current research landscape, and illustrating connections between various studies. Furthermore, it identifies emerging themes within the field and initiates discussions around these evolving topics. Therefore, this review serves to deepen our understanding and stimulate further exploration in the field of ESG disclosure. The results show that ESG assurance, integrated reporting, gender diversity, green innovation, and the environment have been prominent in recent years. We assume that this is an indication of the increasing global awareness of climate change and the pressure from stakeholders to improve accountability, transparency, and companies’ commitment to sustainability. Stakeholders also place importance on the connection between companies’ social responsibilities and their reputation, investor confidence, and financial performance. Furthermore, the identified clusters present potential areas for further research, offering new opportunities for scholars interested in contributing to the field of ESG disclosures and their impact on firm value. Our review not only explores the literature but also organizes it into thematic clusters, benefiting future researchers. This review is also valuable for practitioners and management professionals, as it provides insights into the significance of disclosures and their influence on firm performance, firm value, and sustainable development. Figure 1 illustrates the framework of the study.

2. Methodology

Bibliometric analysis is a widely used method for assessing the impact of publications, which is not possible in other forms of review [25,26]. Bibliometric approaches are highly beneficial for visualizing the framework of a topic, identifying current and emerging research topics, and summarizing the most impactful countries, journals, authors, and publications in a field [27]. This analytical approach is used to analyze performance and science mapping to visualize the structure and evolution of the scientific domain [28,29].

The bibliometric analysis was conducted using the VOS viewer software 1.6.20 developed by van Eck and Waltman [30], R Studio (bibliometrix package) developed by Aria and Cuccurullo [31], and Cite Space developed by Chen [32]. Firstly, the VOS viewer was utilized to build and visualize bibliographic networks because it offers the basic functionalities needed for the visualization of bibliographic mapping networks in the easiest method [33,34]. VOS viewer gathers bibliographic data and creates graphical maps based on bibliographic coupling, co-authorship, the co-occurrence of author keywords, and co-citations [35,36,37]. This software is characterized by its ability to handle larger data volumes, has superior mapping capabilities, and supports all the functions explored in this research [38]. Therefore, we mainly used the VOS viewer in this review to perform an analysis of countries, institutions, journals, and authors. In addition to analyzing the co-authorship and co-citation of countries and authors, we also analyze the hottest and emerging themes in this field. Second, by using Cite Space as a cluster analysis tool, three different types of basic algorithms can be demonstrated, which are inverse document frequency (IDF), mutual information testing (MIT), and log-likelihood ratio (LLR) [39]. In this review, LLR is used to extract cluster labels. Third, we used R Studio (bibliometrix package), which is one of the tools that help facilitate the conduct of bibliometric analysis comprehensively by applying specific tools to implement scientific research and quantitative bibliometric research. So, R Studio is not only seen as one of the most powerful and flexible statistical tools, but it is also referred to as an open-source tool that can be widely shared and used [40]. According to Crawley [41], R Studio represents a broad and integrated set of software applications used in various data processing, calculations, and graphical displays. In this review, R Studio is used to map and visualize the most frequently used keywords. In this review, we also used Pajek to solve the term overlay in the VOS viewer software. In addition to bibliometric analysis, an SLR is used to identify, evaluate, and synthesize the available research relevant to a particular subject area or phenomenon [42]. SLR was used to objectively evaluate and critically analyze the most salient and interconnected themes in analyzing the relationship between ESG and firm value. This methodology is followed to enhance the results of the bibliometric analysis, ensuring that an analytical evaluation of the topic under discussion is conducted and a clear roadmap for future studies is determined. This method has been used by many studies published in highly influential journals among academics, such as in Xu, X et al. [43], Sanga et al. [44], and Chakraborty et al. [45].

On 14 December 2023, a systematic search was conducted using a major multidisciplinary research database (Scopus). Scopus stands as one of the largest and most extensively utilized databases, encompassing millions of articles that have undergone peer review in journals [46], which includes many of the major publishers like Elsevier, Emerald, Springer, Taylor, Francis, and IEEE [47]. In addition, the datasets extracted from the “Scopus database” are useful for descriptive and bibliometric analysis using different software, such as VOS viewer, compared to other databases, such as Google Scholar and WoS [48]. To retrieve the relevant literature in this field, the following keywords were used: (environmental AND social AND governance AND disclosure OR ESG AND disclosure OR corporate AND social AND responsibility AND disclosure OR CSR AND disclosure OR reporting OR sustainability AND disclosure AND “firm value*”). The keywords “ESG” and “CSR” were considered synonyms, as both terms are usually included in relevant research [49,50,51]. According to Christensen et al. [52], the definitions of ESG/CSR and sustainability are very similar, with ESG and sustainability often being expressed by the term CSR. The asterisk in “firm value*” was added to cover similar terms like “corporation” and “enterprise”. The initial search resulted in 8847 studies. We then systematically filtered the sample even further based on the filtering characteristics in the Scopus database. We focused only on subjects that we believed related to the topic of our review and the literature published in peer-reviewed journals. As a result, conference papers and books were excluded. The screening process resulted in 4084 potentially relevant and analyzable articles using these criteria. For a clearer illustration, see Figure 2, which describes the systematic method used to collect the data for this review.

3. Results

3.1. Performance Analysis

The search in the Scopus database revealed 4084 publications containing the terms “ESG disclosure” and “firm value” in their abstracts, keywords, or titles (see Figure 3). Cormier and Gordon [53] published the first research article that examined the social and environmental reporting strategies of three electric utilities that are publicly and privately owned. The literature developed slowly until 2015, but researchers’ significant interest in research publications led to its rapid growth. This increased interest in the topic is likely due to the growing demand for successful ESG outcomes and stakeholders’ views regarding its role in achieving sustainable development, along with financial results [54,55].

As shown in Figure 4, the number of citations for scientific works varies throughout time. Among the nineteen years with publications on this topic, thirteen consecutive years saw more than 3000 citations for publications published during the specific year (2011 to 2023). Despite 2020 witnessing the highest number of citations, 13 articles were not cited until the time of this review, and 137 articles were cited less than 10 times. Furthermore, 23 articles were cited more than 100 times, with most of these publications being published in high-impact journals. Twelve of these articles were published in the journals “Journal of Cleaner Production”, “Corporate Social Responsibility and Environmental Management”, and “Business Strategy and the Environment”. The most cited article in 2020 was published in the “Review of Finance” and focused on Chinese firms. The study aimed to discuss the role of companies in achieving social responsibility and alleviating agency problems in a way that enhances the value and performance of Chinese companies [56]. The most cited article was published in 2011 by El Ghoul et al. [57], which discusses the impact of CSR on the cost of equity capital for United States of America (USA) firms. The results come back with arguments in the literature that corporations with CSR policies and practices have higher valuations and lower risks. The results also show that corporate investment in social responsibility enhances the firm’s value by obtaining less expensive financing and reducing risks. As observed, these articles were published in high-impact journals and conducted in countries with strong economies, which may be one reason for the increased citations of these articles [19]. Although most articles were written between 2020 and 2022, 2018 ranked fourth in the number of citations.

The top 10 countries and authors of articles on this topic are listed in

Table 1. The top 10 countries, institutions, and authors.

No.	Country	TNP	%	Institution	TNP	%	Author	TNP	R%	H-Index	Author’s Country	Author’s Institution	FA
1	China	788	19.29	Universidad de Salamanca, Spain	50	1.22	Uyar, Ali	41	1.00	26	France	Excelia Business School	2012
2	USA	516	12.63	Excelia Business School, France	44	1.08	Kuzey, Cemil	29	0.71	22	USA	Murray State University	2015
3	UK	410	10.04	University of Sfax, Tunisia	43	1.05	Karaman, Abdullah S.	27	0.66	17	Kuwait	American University of the Middle East	2018
4	Italy	271	6.64	University of Portsmouth, UK	41	1.00	Raimo, Nicola	23	0.56	19	Italy	Lum Giuseppe Degennaro University	2019
5	Spain	270	6.61	Universiti Utara Malaysia, Malaysia	40	0.98	Vitolla, Filippo	23	0.56	24	Italy	LUM Jean Monnet University	2019
6	Australia	260	6.37	Xi’an Jiaotong University, China	40	0.98	García-Sánchez, Isabel-maría	22	0.54	55	Spain	Universidad de Salamanca	2013
7	Malaysia	252	6.17	Universitas Airlangga, Indonesia	39	0.95	Hussainey, Khaled	22	0.54	40	UK	University of Portsmouth	2016
8	Indonesia	222	5.44	Brunel University London, UK	35	0.86	Ntim, Collins G.	19	0.47	40	UK	University of Southampton	2013
9	India	210	5.14	FSEG Sfax, Tunisia	35	0.86	Jiraporn, Pornsit	17	0.42	32	USA	Penn State Great Valley	2017
10	South Korea	190	4.65	Universiti Teknologi MARA, Malaysia	33	0.81	Velte, Patrick	17	0.42	26	Germany	Info Leuphana Universität Lüneburg	2006

TNP: total number of publications; FA: first article identified.

. A total of 788 articles contributed by China represent 19.29% of the total literature collected, followed by 516 articles contributed by the USA, representing 12.63%. The United Kingdom (UK) comes after the USA with 410 articles, followed by Italy with 271 articles and Spain with 270 articles. Together, these countries collectively cover 55.22% of the total publications. The analysis results also reveal that Asian countries contribute over 40% (1662 out of 4084) of “ESG disclosure and firms value” publications, emphasizing the prominent academic contributions of Asian countries in this area. We observe that most countries on the list are a mix of developed and developing nations. This may be due to active commercial activities, cultural backgrounds, and a high concentration of academic institutions [58]. In addition, many countries have implemented regulatory systems and launched ESG-themed indices to enhance ESG implementation, including China [59], India [60], and Europe [61]. This has motivated researchers in different countries to investigate this topic.

According to Scopus outputs, many institutions from different countries have contributed to this field. Table 1 categorizes the number of publications for each institution and their respective countries or regions. Among the top ten institutions, seven are from the most productive countries in terms of publications: two each from the UK and Malaysia and one each from China, Spain, and Indonesia. The remaining are from Tunisia (two institutions) and one from France. Interestingly, despite the dominance of countries such as the USA, Italy, Australia, India, and South Korea in this field, their institutions have none of the top ten most productive compared to Tunisia and France. Table 1 demonstrates that the “Universidad de Salamanca” ranked first in the total number of publications (50 publications, 1.22%). Followed by “Excelia Business School”, with 44 publications and 1.08%, and “University of Sfax”, with 43 publications and 1.05%. “University of Portsmouth” and “Universiti Utara Malaysia” follow with 41 and 40 publications, respectively. In terms of ESG disclosure and firm value, the most productive institutions come from three continents: four from Asia, four from Europe, and two from Africa. This highlights the widespread productivity in “ESG disclosure and firm value” across three continents, reflecting the worldwide relevance and interdisciplinary nature of this topic. Asia, Europe, and Africa contribute uniquely due to their diverse economic, cultural, and academic backgrounds. The active academic and corporate sectors in these countries and regions, each with different approaches to corporate governance and sustainability, drive research and publication. This diversity enriches the field with various perspectives and insights, reflecting the universal importance of ESG issues in the interconnected world.

Based on the results that show that more than 1000 authors have contributed to the publications of “ESG disclosure and firm value”, surprisingly, 33 authors published over 10 publications during the period of this review. This concentration of academic output among a relatively small cluster of authors suggests specialized expertise and a strong academic focus in this area. Table 1 shows the top 10 most productive authors; every author has published more than 17 papers. Seven authors belong to 4 out of the top 10 most contributing countries, including 2 each from the USA, Italy, and the UK, and 1 from Spain. Meanwhile, the other three authors are from France, Kuwait, and Germany. It should be noted that three authors belong to the list of the most productive institutions. One institution is from the UK, and the other institution is located in Spain. Both of these institutions are among the top 10 most prolific countries. The third institution is from France. Although China, Australia, Malaysia, Indonesia, India, and South Korea are among the most influential and productive countries in this field, no authors from these countries appear in the list of the top 10. “Uyar, Ali” (France) was the most productive author with 41 publications (1.00%), and he published the first article in this field in 2012. The article discussed the relevance of voluntary disclosure by Turkish companies to market value. The study results showed that voluntary disclosure is related to value; in other words, it affects the firm’s value [62]. “Kuzey, Cemil” ranks second with 29 articles (0.71%), and the author published the first paper on this topic in 2015 [63]. “Karaman, Abdullah S.” ranks third with 27 articles (0.66%). “Raimo, Nicola” and “Vitolla, Filippo” are prominent, with 23 articles (0.56%) each; they published their first research in 2019. The remaining five authors published between 17 and 22 articles (see Table 1). The highest H-index author is “García-Sánchez, Isabel-María”, with an H-index of 55; she is from Spain. She is followed by “Hussainey, Khaled” and “Ntim, Collins G” from the UK, both with an H-index of 40. Additionally, “Raimo, Nicola” and “Vitolla, Filippo” are recent contributors. In 2019, their first publication on this topic was published. The publication examined how national culture influences the quality of integrated reporting through a stakeholder theory approach [64]. This indicates a continual evolution and expansion of research perspectives within ESG disclosure and firm value studies.

Table 2. The top 10 journals.

No.	Journals	TNP	%	IF	Publisher/ Country	Main Research Topics
1	Sustainability (Switzerland)	530	12.98	3.9	MDPI/Switzerland	Environmental Science and Social Sciences
2	Corporate Social Responsibility and Environmental Management	220	5.39	9.8	Wiley/UK	Business, Management, and Accounting, Environmental Science and Social Sciences
3	Business Strategy and the Environment	172	4.21	13.4	Wiley/UK	Business, Management, and Accounting, Environmental Science and Social Sciences
4	Journal of Cleaner Production	119	2.91	11.1	Elsevier/UK	Environmental Science, Engineering, Energy and Business, Management and Accounting
5	Journal of Business Ethics	110	2.69	6.1	Springer/Netherlands	Business, Management and Accounting, Economics, Econometrics and Finance, and Arts and Humanities
6	Corporate Governance (Bingley)	81	1.98	5.6	Emerald/UK	Business, Management, and Accounting
7	Environmental Science and Pollution Research	73	1.79	5.8	Springer/ Germany	Environmental Science
8	Social Responsibility Journal	71	1.74	3.2	Emerald/UK	Business, Management, Accounting, and Social Sciences
9	Cogent Business and Management	53	1.30	3	Cogent OA/ UK	Business, Management, Accounting, and Decision Sciences
10	Meditari Accountancy Research	43	1.05	3.5	Wiley/UK	Business, Management, and Accounting

IF: impact factor.

shows the top 10 journals that have published the most articles on “ESG disclosure and firm value” between 2001 to 2023. The sample of articles included 669 journals from specific or multiple subjects. The top 10 journals account for 36.06% (1472 articles) of all the sample publications. The distribution of publications across various journal types demonstrates significant diversity in journals and fields of study. During the period used in this review (2001–2023), 591 journals published less than 10 studies (88.34%), while 78 journals published the equivalent of 10 or more studies for each journal (11.66%). “Sustainability (Switzerland)” (IF: 3.9) emerged as a leading journal with 530 research papers published, followed by “Corporate Social Responsibility and Environmental Management” (IF: 9.8) with 220 research papers. The third most influential journal is “Business Strategy and the Environment” (IF: 13.4), which published 172 research papers (about 4.21% of the total publications). “Journal of Cleaner Production” (IF: 11.1) ranked fourth with 119 research papers (2.91% of the total publications). These four journals contribute about 25.49% of the total publication output, which indicates their deep focus on “environmental and sustainability issues”. “Journal of Business Ethics” (IF: 6.1) ranks fifth, with 110 research articles. The remaining journals are presented in Table 2. Generally, the journals show a range of multiple disciplines or single disciplines from a multifaceted perspective. This review offers insights into the most exciting professions in this domain. Table 2 shows the top 10 journals covering six different subject fields. Among these top 10 journals, 10% focus on a single subject area, while the remaining 90% cover more than one subject area. “Business, management, and accounting”, represented by eight journals, and “environmental science”, represented by five journals, emerge as the most common subjects.

Moreover, the top 10 journals cover environmental science, business, management, and accounting. Business, management, and accounting are essential subjects that are prominently featured in journals such as “Corporate Social Responsibility and Environmental Management”. Additionally, journals such as “Environmental Science and Pollution Research” and “Business Strategy and the Environment” focus on business, management, accounting, environmental science, and social sciences. The “Journal of Cleaner Production” and “Journal of Business Ethics” address broader topics, including engineering, environmental science, energy, business, management, accounting, econometrics, economics, finance, arts, and humanities. This reflects the comprehensive scope of ESG research, encompassing various ESG issues. On the other hand, among the top 10 journals, 3 (30%) are from Wiley/UK publishers. Two journals (20%) are published by Emerald, and two (20%) are published by Springer. The remaining journals are from various publishers, including MDPI, Elsevier, and Cogent OA. Seven journals are published in the UK, with one each from Switzerland, the Netherlands, and Germany. This shows that all the journals in Table 2 are published in Western countries.

3.2. Network Analysis

Bibliometric data visualization is closely linked to creating a network that maps the study’s interactions. Network analysis is typically used to visualize data derived from bibliometrics and is displayed as a network [65]. This review utilized co-authorship, co-citation, and co-occurrence to visualize the bibliometric network.

Co-Citation and Co-Authorship Analysis

Table 3. The author’s analysis by citation.

No.	Author	Cluster	Links	TLS	Citations
1	García-sánchez, Isabel-maría	4	7	18	1151
2	Martínez-ferrero, Jennifer	4	4	15	1031
3	Raimo, Nicola	1	6	50	996
4	Vitolla, Filippo	1	6	50	996
5	Hussain, Nazim	3	4	5	820
6	Rubino, Michele	1	5	28	734
7	García-meca, Emma	4	4	7	503
8	Cuadrado-ballesteros, Beatriz	4	3	7	489
9	Pucheta-martínez, María Consuelo	5	3	14	416
10	Sial, Muhammad Safdar	2	4	6	406

TLS: Total link strength.

shows the top 10 authors with the most citations. “García-Sánchez, Isabel-María” is the most influential author in this discipline, with 1151 citations. Followed by “Martínez-Ferrero, Jennifer”, who ranks second with 1031 citations. “Raimo, Nicola” ranks third, with 996 citations. The remaining authors are listed in Table 3.

It should be noted that cooperation among researchers enhances communication and productivity within the academic community. In Figure 5, we use a VOS viewer to illustrate the cooperative relationships among authors. The minimum number of articles and citations by an author was set at 6 and 10, respectively. Among over 1000 authors, 22 met the selection criteria.

Figure 5 depicts network findings in five clusters. Each cluster is led by one or more core authors. For example, cluster 1 (red), represented in red, includes “Raimo, Nicola”, “Vitolla, Filippo”, “Rubino, Michele”, “Salvi, Antonio”, “Giakoumelou, Anastasia”, and “Petruzzella, Felice” and is the dominant cluster containing the most cited authors. Cluster 1 (red), cluster 2 (green), cluster 3 (blue), cluster 4 (yellow), and cluster 5 (purple) are centered around the most cited author. Cluster 1 is centered around “Raimo, Nicola”and “Vitolla, Filippo”, while clusters 2, 3, 4, and 5 are centered around “Sial, Muhammad Safdar”, “Hussain, Nazim”, “García-Sánchez, Isabel-María”, and “Pucheta-Martínez, María Consuelo”, respectively. We observe that three authors out of the five clusters are from the top ten authors’ productivity list. These authors are the most frequently cited and probably have had the most significant influence on this field globally. The co-authorship network displays the relationships among the most active authors in the field of “ESG disclosure and firm value”. Figure 5 also indicates well-developed collaborations and communication, with links between the five clusters. The thickness of the lines between some authors in the “Vitolla, Filippo” and “Raimo, Nicola” research clusters reflects the strength of their closely related work. Improved and frequent collaboration among the most influential researchers could lead to significant advances in this field of research in the future. We observe that cluster 4 (yellow) is connected to the other five clusters, indicating that it includes references that are more similar to those in the other clusters.

Many countries and regions have established robust cooperative relationships. China, the USA, and the UK lead in the number of collaborative publications and country collaborations. Although India and Spain have collectively published over 200 research papers, they have formed a maximum link strength (MLS) of only 11 with Italy and the USA, respectively. Based on countries, co-authorship analysis was conducted by setting a minimum threshold of 50 articles for a country, resulting in 29 countries meeting this criterion. Figure 6 illustrates a collaboration network between significant countries participating in this field. The color indicates which cluster countries belong to based on the strength of their relationship, the circle size represents the number of articles, and the lines among the circles indicate the links.

We have five clusters in Figure 6. Cluster 1 (red) is led by the UK and includes several countries from various continents see Figure 6. Cluster 2 (green) is dominated by China and includes some Asian countries/regions, such as Taiwan and Hong Kong (affiliated with China), South Korea, Vietnam, and North American countries (USA and Canada). Cluster 3 (blue) is led by Pakistan and includes some countries located on the continent of Europe, like Italy, the Netherlands, Spain, Germany, Poland, and Romania. Cluster 4 (yellow) is headed by Australia and includes countries from various continents, such as New Zealand (Oceania), Thailand (Asia) and South Africa (Africa). Cluster 5 (purple) is dominated by France and includes Kuwait and Turkey. Among 132 countries, China, the USA, the UK, Canada, Australia, and others have the highest cooperation density, as depicted in Figure 6. China has the highest cooperation density (27 links and 438 LTS), has formed the largest partnerships and academic collaborations with other countries, and has established strong academic ties with the USA and the UK. The thickness of the line indicates the level of cooperation strength, as seen in the red and green clusters in Figure 6. The MLS connects China and the USA (62), China and the UK (58), and China and Australia (35). The USA has 25 links and 421 LTS. Additionally, the USA established the MLS with Canada (49), the USA, and France, each with a link strength of 38. We observe significant connections and cooperation among different countries and regions across multiple continents. These partnerships between clusters can be enhanced by economic factors (especially strong collaboration among the three major economies “China, the USA, and the UK”), language clusters, and the geographical proximity of countries.

Table 4. The most co-citation authors.

No	Author	Institution	Country	Citations	TLS	Cluster
1	Serafeim G	Harvard Business School	USA	1892	21,645	1
2	Jensen M. C	Harvard Business School	USA	1794	19,144	4
3	Jo Hoje	Santa Clara University	USA	1614	20,701	1
4	Freeman R. E	University of Virginia	USA	1371	14,369	2
5	Garcia-sanchez I.M	Universidad de Salamanca	Spain	1348	14,043	3
6	Ioannou I	London Business School	UK	1262	16,451	1
7	Tsang A	Southern University of Science and Technology	China	1241	16,010	1
8	Guedhami O	SKK Graduate School of Business	South Korea	1212	16,091	1
9	Mcwilliams A	University of Illinois at Chicago	USA	1174	14,246	2
10	Shleifer A	Harvard University	USA	1156	12,275	4

presents the top 10 authors ranked by co-citation. Three authors were co-cited more than 1500 times, namely “Serafeim G”, “Jensen M.C”, and “Jo Hoje”. Additional authors were cited over 1000 times, as shown in Table 4. It is also worth mentioning that the top 10 co-cited authors are affiliated with the most productive countries. We also observe that the top 10 co-citation authors are from the most productive countries. Among them, six are from the USA: “Serafeim G”, “Jensen M.C”, “Jo Hoje”, “Freeman R.E”, “McWilliams A”, and “Shleifer A”, while the other authors are from different countries, as shown in Table 4. We observe that several authors are affiliated with the same university and have made substantial contributions to clarify the influence of ESG disclosure on company value. This suggests that the institution has many experts, enhancing its status as a central and specialist research in this field. Their combined research contributes to possible collaborations that enhance the existing literature on ESG practices and their impact on company value.

Table 5 shows the top 10 references based on co-citation. We set a minimum of 100 citations for a cited reference; only 27 references met the criteria. Freeman [66] was the only reference co-cited over 400 times, possibly due to the long publication period of these articles. Overall, the top 10 references were co-cited more than 100 times, as indicated in Table 5. Within these top 10 co-cited references, three were sourced from the “Journal of Business Ethics”, one from a book, and the remaining eight from different journals.

During the period from 2001 to 2023, “Serafeim G” and “Ioannou I” often collaborated on research articles with various authors, including Cheng et al. [67]. Similarly, “McWilliams A” and “Siegel D” published one of the most co-cited articles, see Table 5. One of the most co-cited publications by “Serafeim G” was “Corporate Social Responsibility and Access to Finance” by Cheng et al. [67], where he was a co-author with “Cheng B” and “Ioannou I”. Their paper investigates whether firms with superior CSR performance have better access to financing. The results suggest that companies with better CSR performance encounter significantly fewer capital constraints. According to the Scopus database, “Serafeim G” has published over 50 documents since 2010, with an h-index of 28 in 2023. The articles by “Serafeim G”, along with the works of “Jensen M.C”, “Freeman R.E”, and “Garcia-Sanchez I.M”, have been cited multiple times, each belonging to a distinct cluster (refer to Figure 7).

“Serafeim G” is positioned at the center among all authors. We conducted a follow-up analysis on the authors of the top 10 co-citation references. “Serafeim G” had direct and indirect academic collaborations with many authors, resulting in 3 links and 21645 total links strength (TLS). Furthermore, “Serafeim G.” established a direct collaborative relationship with “Ioannou I” on the impact of Corporate Social Responsibility (CSR) on firm value, as well as with “Jo Hoje and Harjoto M.A” [68]. Figure 7 highlights the collaborative network and the significant contributions of the top 10 authors based on co-citations.

Out of the top 10 co-citation references, 4 were published by the top 10 co-cited authors, as shown in Table 5. One reference closely aligned with this topic, which is “corporate governance and firm value, [68]”, while the others focused on CSR, stakeholders, and other topics.

Although “Serafeim G”’s articles are among the most co-cited publications, his single paper was not the most co-cited in “The impact of ESG disclosure on firm value”. The most commonly cited reference was [66], which focuses on how value can be created for stakeholders through conducting business based on a global view of business and capitalism with ethics.

Jensen M.C ranked second in co-citation, with 1794, and his article received the second-highest number of co-citations [69]. His work examined the intersection of agency, financing, and property rights theories to explore the effects of ownership structure on company behavior, cost, and efficiency. He finds that as the managing partner’s ownership share increases, agency costs decrease, and a balance between the benefits and costs of debt and equity financing can reduce financing costs. The company is conceptualized as a nexus of contracts among multiple individuals with varied objectives, elucidating the rationale behind the existence, structure, and ownership of companies.

According to the cluster analysis, the top 10 co-citation references were cited together in three different clusters: four references in the red cluster, four references in the blue cluster, and the last two references in the yellow cluster (see Figure 8 and Table 5). Each cluster focuses on a different topic, specifically the impact of ESG disclosure on firm value. Cluster 1 (red) includes research papers that primarily explore foundational theories and models that link CSR and firm performance, including stakeholder theory and social performance. For example, Freeman [66] focuses on how value can be created for stakeholders through conducting business based on a global view of business and capitalism with ethics. Meanwhile, Servaes and Tamayo [70] show that CSR is positively related to the company’s value if customers have high awareness and there are large advertising expenditures, which confirms that ESG may add value to the company, but only under certain cases and circumstances and not in all cases. Additionally, McWilliams and Siegel [71] confirm that CSR has a neutral relationship with financial performance as an added value to firms. The results also show that several factors, including consumer income, advertising, research and development, company size, level of diversification, and labor market conditions, measure CSR.

Cluster 2 (green) emphasizes governance, specifically the impact of board composition and culture on CSR, corporate reputation, and board gender diversity. Bear et al. and Rossi et al. [72,73] confirm the importance of gender diversity as one of the CSR classifications in adding value to the company and improving its reputation. Cluster 3 (blue) explores the strategic and financial impacts of CSR initiatives, examining how CSR affects finance accessibility, voluntary disclosure practices, and the conflict between shareholder interests. The literature indicates a multifaceted link where ESG disclosure impacts firm value through various channels, from theoretical frameworks to practical governance and strategic financial outcomes, in addition to governance practices, financial transparency, assurance, gender diversity, accountability, auditing, and stakeholder engagement.

Table 5. The top 10 co-citations references.

No	References	Author (s)	Journals	TLS	Citations	Cluster
1	[66]	Freeman R. E	-	698	415	1
2	[69]	Jensen M.C., Meckling W. H	Journal of Financial Economics	786	369	2
3	[74]	Orlitzky M., Schmidt F.L., Rynes S. L	Organization Studies	715	240	1
4	[67]	Cheng B., Ioannou I., Serafeim G	Strategic Management Journal	597	211	3
5	[70]	Servaes H., Tamayo A	Management Science	513	192	1
6	[75]	Dhaliwal D.S., Li O.Z., Tsang A., Yang Y. G	The Accounting Review	477	189	3
7	[76]	Barnea A., Rubin A	Journal of Business Ethics	614	188	3
8	[71]	Mcwilliams A., Siegel D	Academy of Management Review	550	185	1
9	[68]	Jo H., Harjoto M. A	Journal of Business Ethics	555	175	3
10	[72]	Bear S., Rahman N., Post C	Journal of Business Ethics	380	166	2

Table 5. The top 10 co-citations references.

No	References	Author (s)	Journals	TLS	Citations	Cluster
1	[66]	Freeman R. E	-	698	415	1
2	[69]	Jensen M.C., Meckling W. H	Journal of Financial Economics	786	369	2
3	[74]	Orlitzky M., Schmidt F.L., Rynes S. L	Organization Studies	715	240	1
4	[67]	Cheng B., Ioannou I., Serafeim G	Strategic Management Journal	597	211	3
5	[70]	Servaes H., Tamayo A	Management Science	513	192	1
6	[75]	Dhaliwal D.S., Li O.Z., Tsang A., Yang Y. G	The Accounting Review	477	189	3
7	[76]	Barnea A., Rubin A	Journal of Business Ethics	614	188	3
8	[71]	Mcwilliams A., Siegel D	Academy of Management Review	550	185	1
9	[68]	Jo H., Harjoto M. A	Journal of Business Ethics	555	175	3
10	[72]	Bear S., Rahman N., Post C	Journal of Business Ethics	380	166	2

3.3. Research Topics Analysis

In order to have a deeper understanding of this research field, alongside probing the prolific authors, countries, and institutions, it is also crucial to examine the terms used within it. Figure 9 and Figure 10 illustrate a keyword analysis of the influence of ESG disclosure on firm value. The analysis aims to determine the crucial keywords related to the concept. These keywords represent a compilation of the author’s designated keywords, which best capture the written content. Figure 9 displays the most frequently used keywords.

As shown in Figure 10, the terms related to this topic are spread out among four vertical clusters, each distinguished by different colors. Each cluster consists of many keywords that are multidirectional in nature. The “red cluster”, which includes many terms (refer to Figure 10, red color), is the cluster with the highest frequency of terms. This cluster is led by CSR, the most common term, with 1364 occurrences, 113 links, and 1777 TLS. CSR has established MLS with various terms within and outside the cluster, like “financial performance” with 108 and “firm value” with 75 MLS in the same cluster. Moreover, CSR has been associated with “corporate governance” in the green cluster, “sustainability” in the blue cluster, and “sustainable development” in the yellow cluster, with 236, 124, and 56 MLS, respectively. The green cluster includes many terms, with the most significant one being depicted by the green color in Figure 10. This cluster is led by “corporate governance”, the second most frequent term with 1015 occurrences. “Corporate governance” has formed 112 links and 1663 TLS with many terms in the same and other clusters. Additionally, corporate governance has formed MLS within its cluster, with a “board diversity” of 89. It has also formed MLS with “financial performance” and “firm value” with 62 and 50, respectively, in the red cluster; “sustainability” and ESG with 45 and 30, respectively, in the blue cluster; and “disclosure” and “sustainable development” with 30 and 19, respectively, in the yellow cluster. The “blue and yellow clusters” are each led by “sustainability” and “sustainable development”. The two terms ranked third and fourth in terms of occurrences, with 417 and 252 occurrences, respectively. These two terms have also formed MLS with the terms in the other clusters, especially financial performance and firm value.

The cluster analysis reveals a dense network of terms interconnected through strong and noticeable links. This interconnectivity emphasizes the cohesive and integrated nature of research in this field. It is important to note that key terms such as “financial performance” and “firm value” play a central role in these clusters, highlighting the significant correlation between sustainable disclosures, corporate governance, and the key financial outcomes of firms. These findings suggest that sustainability and governance practices are not merely compliance measures but are essential to a company’s financial performance and valuation.

Furthermore, an interesting observation is the role of firm size in this network. The size of a company appears to be linked not only to its disclosure practices but also serves as a mediator between these practices and financial outcomes, such as performance and value [77,78]. This suggests that the impact of sustainability and governance practices on a company’s financial performance could vary based on the company’s size. Larger companies, because of their greater resources and visibility, may experience a more significant influence of these practices on their overall value and performance [77,79]. This deeper understanding adds complexity to the analysis, as it emphasizes that the size and scale of the business can impact the disclosure of sustainable practices and ESG. This offers a more detailed perspective on the dynamics in this field. Additionally, the analyses indicate that disclosing ESG issues is closely connected to firm value. It impacts firm value through various channels, including governance practices, sustainability efforts, transparency, accountability, assurance, and innovation. This highlights the increasing significance of ESG in the corporate world and its substantial influence on financial performance and market valuation [10,80].

To better understand this research area, we conducted a review of the key terms frequently used by authors in Figure 11. As observed, there is a significant increase in the frequency of terms post-2015, aligning with our findings from the literature trend analysis per year. The prominent keywords were CSR, corporate governance, ESG, sustainability, and firm value. The increased interest in these terms post-2015 may be attributed to the interest of organizations, such as the United Nations and the Paris Agreement, which are committed to achieving sustainable development [1]. The analysis indicates that defining a clear impact of ESG disclosure on firm value is challenging due to the complex and unclear relationship between these concepts [81]. More developments are needed to investigate whether ESG disclosure positively affects firm value in different contexts, countries, and industries. This has resulted in recent trending topics in this area, including “assurance, bibliometric analysis, systematic literature review, COVID-19, green innovation, SDGs, ESG performance, financial distress, ESG disclosure, board gender diversity, and sustainable finance”, which may indicate future research trends (refer to Figure 11 and

Table 6. Research agenda.

	Future Research Questions and Topics
ESG practices and firm value in regulatory environments	How can legal, cultural, and societal differences in ESG practices and their impact on firm value be interpreted in different organizational contexts? What are the main mechanisms and strategies through which ESG practices can enhance the value of firms? Is there a difference across different countries, industries, and cultures? Investigate the role of ESG on firm value based on industry type, ownership type, and company location.
ESG practices and firm value, and new themes	Investigate the extent to which causal factors such as emission-related actions, workforce, innovation, and corporate strategy regarding social responsibility affect firm value. Investigate the impact of gender diversity in enhancing the relationship between ESG and firm value. Investigate the role that ESG assurance plays in enhancing firm value. How can auditing enhance the impact of ESG practices on firm value?
ESG dimensions and firm value	How does the impact of mandatory disclosure and voluntary disclosure on ESG practices differ on firm value? How do the effects of the “E” OR “S” OR “G” dimensions differ in enhancing firm value?
Theory	How can a more comprehensive knowledge of the relationship between ESG and corporate value be achieved by utilizing and integrating agency theory, stakeholder theory, and value-enhancing theory? In what ways do these theories complement or intersect with each other in explaining how to enhance firm value through ESG practices?
Country/data collected	Given that ESG disclosures are a global phenomenon, research should be conducted on this topic in African, Arab, and European countries that currently lack representation.

). The blue-colored nodes indicate keywords that are used most frequently in previous literature, while the red-colored nodes represent keywords that are used in the literature from a more recent posting year [33]. For example, since the outbreak of COVID-19, ESG investments have gained unprecedented attention among investors and scholars. Figure 11, shows that as the number of word occurrences increases, the color becomes darker.

As depicted in Figure 11, we observe the presence of certain terms in the initial period (pre-2015) and the absence of others from the roster in the subsequent period (post-2015). The absence of certain terms/words from the first period (pre-2015) in the subsequent period within the top 20 keywords by frequency could be attributed to various factors. First, these terms/words may have been used less, or they may have been used in the same amount or more during the first period (pre-2015). However, the heightened interest in certain other terms post-2015 has hindered the inclusion of these terms in the list. For example, “voluntary disclosure” received a frequency of 9 in the first period (pre-2015). At the same time, “voluntary disclosure” received a frequency count of 44 in the second period (post-2015). Therefore, it was not included in the top 20 keywords list by frequency, as illustrated in Figure 11, with the final keyword on the list having a frequency of 78. Compared to other terms in the second phase (post-2015), we observe that “voluntary disclosure” was utilized less or received less focus as certain countries or regions began to enforce mandatory disclosure. For example, Felicia et al. [82] reported that Hong Kong was the first stock market in Asia to impose mandatory ESG disclosure requirements in 2016. Similarly, the term “annual reports” has disappeared from the list starting from the second period (post-2015), possibly because of the heightened interest and growing awareness among investors and all stakeholders in reporting ESG/CSR issues [83,84].

Second, terms or words that emerged in the second phase, such as “COVID-19”, were initially discovered in December 2019 and declared a pandemic virus by the World Health Organization on 11 March 2020 [85]. This epidemic has created ethical, health, and economic issues due to quarantine and has revealed social issues that require new strategies and initiatives [86]. In this context, there has been a growing interest in the academic world regarding ESG issues. Since 2020, there has been a proliferation of academic articles on ESG issues and COVID-19 covering different areas of interest [87].

Third, the terms that significantly developed in the second phase (after 2015), such as “stakeholder theory”, which assumes that a company or organization should create value for all stakeholders and not just shareholders, as well as everyone who has a stake in the company or organization, including employees, suppliers, customers, investors, and the socially engaged [88,89]. This theory is relevant to companies that promote efforts to help protect the environment, seek to improve social welfare and community relations, and often commit to governance practices that maximize value [90]. In this context, we observe that there is a close alignment with the principles of ESG, which is a framework system that includes environmental (E), social (S), and governance (G) factors [91]. Moreover, there has been an increased interest in ESG issues, especially in recent times [92]. This increase aligns with our findings from analyzing the data (refer to Figure 11). So, we observe that stakeholder theory is commonly utilized as a theoretical framework in the ESG literature [93]. Regarding agency theory, there is a growing interest among researchers in utilizing it. This is because of the debate surrounding the theory’s view on the effect of implementing ESG activities on a firm’s value. This theory suggests a negative relationship, as engaging in ESG activities could lead to agency problems between shareholders and managers [55]. Implementing ESG initiatives may negatively impact the company’s profits, which is not in the shareholders’ best interest. On the contrary, it may benefit the personal interests of managers [76,94]. Additionally, Rastogi et al. [95] propose that the outcomes of disclosure, transparency, and ownership are greatly influenced by agency theory. Therefore, the interest in utilizing these theories may stem from the lack of agreement in the literature concerning the connection between engaging in ESG activities and their influence on the firm’s value.

Theoretically, recent trends show a shift towards stakeholder theory, driven by a growing focus on sustainability and corporate responsibility beyond just shareholders. This shift confirms the importance of ESG factors in company valuation and prioritizes ethics over mere financial performance and regulatory compliance. This shows the theoretical advancement in the research field, as depicted in Figure 11. For instance, the agency theory was mentioned six times in the first phase and increased to 78 times in the second phase. According to agency theory, ESG disclosure contributes significantly to reducing the asymmetry of various information among all stakeholders, including shareholders, agents, and managers [96]. In this regard, companies disclose their ESG-related activities to ensure that information asymmetry is reduced [97]. Therefore, enhancing the disclosure of diverse environmental and social initiatives by corporate leadership is deemed as supplementary non-financial data that enhances the organization’s workplace atmosphere and standing. It also helps to reduce the knowledge barrier between shareholders and the company, which, in turn, contributes to adding value to the firms [98]. Similarly, stakeholder theory was mentioned 101 times in the third phase, indicating its growing prominence and relevance in this research area. A stakeholder is any individual or group of individuals who can influence or be influenced by the goal of an organization or company in order to achieve its objectives [99]. Therefore, the company has a responsibility toward stakeholders such as suppliers, customers, employees, the government, and society as a whole [100]. Stakeholder theory is applicable to companies that prioritize environmental protection, strive to enhance social welfare and community relations, and adopt governance practices that enhance value [90]. Based on this theory, a company will be more successful if it can manage its relationships with all stakeholders effectively. A company with a stronger ESG profile can achieve higher growth than a company with a relatively weaker ESG profile [55]. Chauhan and Kumar [101] concluded that non-financial information voluntary disclosure, such as ESG disclosure, is preferable and expected to positively influence stakeholders’ and investors’ perceptions. However, stakeholder theory sees ESG activities as aligning with stakeholder interests and can improve a company’s performance and value. Figure 12 displays the trend of keywords by year.

3.4. Clusters Analysis

To analyze the intellectual framework of the research field, we used Cite Space (refer to Figure 13) to identify the primary research topics within each cluster. The results of the Cite Space analysis show that six topics were prominent in the sample: “Social, sustainable development, ESG, organization, innovation, and stakeholder”. This analysis helps to comprehend the interconnections within the conceptual network regarding the influence of ESG disclosure on firm value.

3.4.1. Social Cluster

This cluster is the first in which the word “social” appeared more frequently than any other word. In this cluster, carbon emissions are clearly evident. Some studies in this compilation emphasized the significance of implementing and practicing carbon management to improve firm value. Shen et al. [102] showed that implementing carbon management, such as external carbon assurance, carbon communication, and setting carbon reduction goals, has a positive and important relationship in enhancing the company’s market value. Jiang et al. [103] showed that companies that have large disclosures about carbon have great value. Likewise, Dewaelheyns et al. [104] showed that the firm’s value is negatively affected if carbon risks increase. Shrestha et al. [105] also showed that the carbon management system works to mitigate the negative impact of carbon emissions on the firm’s value. Future research should explore the correlation between carbon emissions and company value in emerging markets like India, Malaysia, and Indonesia, which boast significant populations and industries. On the other hand, CSR may be an important area of investigation in future studies. For example, Zhang and Yang [106] stated that there is limited knowledge about how companies can use social responsibility communications in managing crises. It should be noted that companies’ efforts to practice CSR have a significant relationship with enhancing the legitimacy of corporate actions. This is highlighted by the emergence of legitimacy theory in this field, which has been extensively utilized in research studies [107,108,109,110]. It should be noted that some studies, such as [111], reported that legitimacy theory is considered one of the most important applicable theories regarding directing environmental practices and activities.

3.4.2. Sustainable Development Goal Cluster

Sustainable development refers to the mechanisms and agenda that will work to reform and address various ESG issues. Therefore, to enhance the firm’s value, the company must define, measure, and monitor SDGs [112]. Sun et al. [113] showed that high performance and good financial results are important for reducing financing costs, promoting sustainable development, and achieving high value for the company. Matuszak-Flejszman et al. [114] reported that achieving sustainable development has become linked to ESG performance. At the same time, Calabrese et al. [115] showed a close relationship between the importance of enhancing environmental responsibility, setting development goals, and adding value to firms. It should be noted that the bibliometric analysis revealed that sustainable development ranked second, featuring keywords like SDGs and the European Union. This is an indication of researchers’ interest in examining how to achieve the SDGs for the year 2030 by European Union countries [116,117,118,119]. Future studies may use different environmental factors in emerging countries to investigate the relationship between ESG and achieving the SDGs set by the United Nations and their role in enhancing corporate value.

3.4.3. ESG Cluster

In light of the widespread and significant interest of all stakeholders in the importance of ESG integration and its standards [120], the focus of the business media on applying ESG standards has increased in recent years. The term ESG includes three indicators: E, which is the indicator through which the environmental activities practiced by the company are measured; S, which measures the company’s practices towards suppliers, customers, employees, society, and other stakeholders; and G, which refers to governance standards, including information about the structure of the board of directors, rights, shareholders, functions of boards of directors, and mechanisms for corporate governance [121]. It is one of the most important means of improving the financial performance of companies and enhancing their value [122]. Implementing ESG standards reduces agency problems with stakeholders and reduces debt defaults [123]. On the other hand, research has shown that companies benefit from performing well and being distinguished in terms of ESG. This attracts investors, helps manage risks, enables effective competition, and leads to high profits [124]. However, some studies called for the need to determine the relationship between ESG, and firm value based on each ESG component. For example, Mardini [125] shows that the company’s performance is positively affected by governance and environmental factors, while it is negatively affected by social factors. Kong et al. [126] indicated that governance does not affect firm value, while environmental and social performance have a positive effect. Gregory et al. [127] argue that companies’ adoption of their ESG responsibilities is evidence of their commitment to their social duties imposed by the government and society. On the other hand, Kim et al. [128] show that one of the factors that weakens the relationship between ESG and firm performance is the largest number of shareholders. Additionally, Duan et al. [124] found that the impact of ESG performance on firm value depends on the company’s location, ownership, and industry type. The results showed a positive effect for companies that contribute highly to polluting, non-state-owned companies, and companies located in the eastern regions of China, while there was a negative effect for other cases. Despite increasing studies discussing the role and impact of ESG practices on firm value, there is a lack of agreement between the results of these studies [10,129,130]. Therefore, further research is necessary to investigate the factors and causes that have contributed to the variations in outcomes. This can be accomplished by conducting comparative studies and research in evolving organizational settings.

Mandatory versus Voluntary ESG Disclosure

Government guidelines can be viewed as one of the most important means of communicating sustainability. In this regard, some countries are introducing new requirements and laws that regulate the preparation of ESG reports through corporate laws or accounting regulations. China requires companies to report their environmental practices and activities in accordance with the law issued in 2008 [131]. As a result of the general trend to achieve a green environment and sustainability, the level of mandatory ESG disclosure has significantly increased, which is an indication of enhancing the transparency of ESG standards. This is reflected in enhancing the firm’s value [131]. However, it cannot be confirmed whether the effect of mandatory disclosure has contributed more to enhancing the firm’s value compared to voluntary disclosure [132]. Although mandatory disclosures are prevalent, voluntary disclosures are also on the rise [131]. Therefore, it is uncertain whether mandatory disclosure has had a greater impact on increasing the company’s value compared to voluntary disclosure [132]. Further research could investigate this in future studies.

Regional and Cultural Contexts and ESG Disclosure

The findings of certain studies, such as Helfaya and Aboud [133], validate the influence of cultural dimensions in a country on improving and boosting ESG disclosures by leveraging feminine cultures and individualism. On the other hand, Roy and Mukherjee [134] found that the national culture of the state has an important influence on promoting ESG disclosure. Wasiuzzaman and Kawi [135] argued that cultural factors such as masculinity and power distance can play a role in enhancing the impact of ESG disclosure on the value and performance of companies. In this context, we argue that cultural diversity and regional contexts greatly influence ESG disclosure. Thus, further research could enrich the insights of the scarce literature by conducting comparative studies in various cultural and organizational environments.

3.4.4. Organization Cluster

Within the framework of this research, the concept of organization is linked to many terms, including ESG and environmental protection. This indicates that the organization has an impact on social, environmental, and financial regulatory practices. In this context, Chouaibi et al. [136] indicate that organizations that adopt green practices and give importance to ESG disclosure have a higher market value and better financial performance. This indicates the interconnectedness of processes within the organization and ESG factors. In this regard, Albuquerque et al. and Duan et al. [124,137] indicate that companies that adopt green and sustainable practices attract more investors and lower the risk, which reflects positively on the firm’s value.

3.4.5. Innovation Cluster

The analysis results in Figure 13 indicate that innovation ranked fifth among the clusters identified as one of the most important topics linking ESG and company value. The firm’s value can be achieved through two types of resources: tangible resources, such as capital and assets, and intangible resources, such as reputation, intellectual capital, and intellectual property, represented by innovations. Therefore, innovation is of great importance in adding value and improving the performance of social responsibility by enhancing the company’s reputation and capital [138]. So, the reputation resulting from innovation is a real and effective resource in enhancing the firm’s value. The results of Khalil and Nimmanunta [139] show that green and traditional innovation has a positive impact on the firm’s value. The results also indicate that ESG innovation has an important financial impact and contributes to attracting environmentally related potential in advance. On the other hand, Zhang et al. [140] showed that innovation has a positive impact on the firm’s value when it is mixed with ESG performance. Therefore, the greater the firm’s value, the greater the social performance. Khalil et al. [141] divided innovation into two parts: an important environmental innovation that enhances the company’s value and a traditional innovation that negatively affects the firm’s value as a result of activating carbon emissions, which affects ESG performance. Kong et al. [126] showed that innovation works as a catalyst in improving the relationship between ESG performance and firm value, which contributes to implementing practices with high efficiency and achieving sustainability. Finally, it can be said that innovation contributes to improving the role that ESG performance plays in adding value to firms, especially in light of rapid environmental changes and facing sudden crises such as COVID-19.

3.4.6. Stakeholder Cluster

With the rise in skepticism and the decline in direct trust, the monitoring of companies’ performance concerning ESG is consistently being carried out. Stakeholders are persistently pushing for companies to integrate ESG objectives into their operations and strategic frameworks [124]. In this regard, stakeholders link audit quality as one of the most important means of enhancing social responsibility and governance, improving the company’s value, and enhancing its reputation [142]. Likewise, Kheireddine et al. [143] confirm that sustainability assurance plays an important role in strengthening the relationship between environmental sustainability performance and improving the firm’s value. However, the results of some studies indicate that the influence of stakeholders on firm value has not been adequately investigated [106]. On the other hand, some studies show that the high firm value resulting from the company’s implementation of its social responsibilities adds positive value to stakeholders [144]. This cluster came in the last classification, and Figure 13 shows the presence of several other interconnected words, such as carbon emissions, accountability, and transparency. Future research could improve the existing literature by exploring how corporate leadership enhances stakeholder value and the conflict of goals between stakeholders and shareholders. Furthermore, future studies could examine the significance of external assurance and audit quality in improving the transparency of ESG disclosures and their influence on enhancing firm value.

4. Future Research Agenda

Studying the impact of ESG disclosure on firms’ value is an important area of research, especially in recent years. In this regard, the largest database was used to obtain literature discussing ESG and its role in enhancing the value of the company. The impact of ESG on firm value is not well explained in the literature due to a lack of agreement between the results [145]. A biometric analysis supported by SLR analysis was conducted to prepare a framework and roadmap for future research based on the analysis and research gaps. Mainly based on Figure 11 and Figure 12, Table 6 presents some suggestions for future work, while researchers can also use Figure 12 and Section 4 to determine research directions in a comprehensive way.

5. Conclusions and Limitations

5.1. Conclusions

The growing focus on sustainability has led to an increase in companies sharing details about their ESG practices. This surge in ESG disclosure has triggered continuous discussions about its influence on a company’s value, prompting a consistent expansion in research in this field. This review aimed to conduct a bibliometric analysis supported by SLR analysis to discuss the literature that investigated the impact of ESG on firm value during the period between 2001 and 2023. A thorough analysis of 4084 articles shows a steady rise in the volume of publications on this subject, particularly from 2015 to 2023, with a rise in 2023 (RQ1). Regarding the countries, institutions, authors, and journals with the greatest influence in this area (RQ2), China and the USA emerged as the leading contributors, each responsible for more than 500 publications. Additionally, there was a significant academic relationship between the two countries. Spain’s University of Salamanca had the highest number of publications, with 50 articles, and “Uyar, Ali” was the most contributing author, with 41 articles. Furthermore, the journals “Sustainability”, “Corporate Social Responsibility and Environmental Management”, “Business Strategy and the Environment”, “Journal of Cleaner Production”, and “Journal of Business Ethics” have had a substantial impact in this field. “Sustainability” stands out as the most influential journal with over 500 publications. Additionally, we illustrated the co-citation network graph to identify and gain insights into the most influential countries, authors, and references in this field. These findings can greatly help researchers gain a deeper insight into the most impactful countries, institutions, authors, and journals in this field while also uncovering the connections between bibliographies and generating fresh ideas. Additionally, they provide valuable perspectives on the academic performance of countries, institutions, authors, and relevant journals.

This review paper also illustrates the intellectual framework and potential emerging topics (RQ4) in the area of the impact of ESG disclosure on firm value. We analyzed cluster analysis (RQ5) to generate a conceptual map of the existing knowledge on this topic. By analyzing co-words, we identified distinct thematic clusters, each representing a set of closely related terms and ideas in the field of ESG disclosure and its influence on firm value. The present scientific production output on this topic is organized into six distinct thematic clusters: society as a central theme, “sustainable development goal”, ESG, organization, innovation, and stakeholders. Additionally, we analyzed the content of these terms and provided suggestions for future research. Furthermore, we visualized the results of keyword clustering and highlighted emerging terms, which provide several avenues for further research (RQ6).

This review has theoretical and practical implications. First, it offers valuable insights into the overall impact of this bibliometric analysis on ESG research and its influence on firm value. Second, it affirms that bibliometric analysis is a potent tool for comprehending the growing body of literature in a specific research field. We determined the protocol of this review including co-citation analysis, co-authorship analysis, and theme mapping. This clear methodological design provides a replicable model for future bibliometric research across different disciplines, contributing to methodological advances. Third, researchers can also use our study findings to select suitable journals for their future work, recognize the most significant and influential authors in this field, refer to their literary works, and gain insights from them. In addition, it is essential to identify the countries and institutions that play a significant role in establishing academic relationships and deriving benefits from authors’ academic experiences. This will contribute to the development of the research field and promote the exchange of knowledge and innovation. Furthermore, it is important to highlight key areas of interest and unexplored topics, as well as to explore future research methodologies in this field. The results of this review also provide important evidence about the significance of disclosing ESG activities in enhancing the firm’s value and the potential for it to have a positive impact on investor responses. This, in turn, assists investors in making better investment decisions and increasing their confidence in the company. Additionally, this review emphasizes the importance of cultural diversity among countries when establishing goals and strategies to achieve society’s goals and aspirations as well as work objectives or when aiming to set uniform global standards. Fourth, this review paper emphasizes the importance of disclosing ESG information, which plays a vital role in enhancing the value, reputation, and performance of companies and driving sustainable development. This study highlights the importance of the research field and offers a roadmap for future research to support the continuous development and advancement of ESG research.

5.2. Limitations

This review has some limitations. First, it solely focuses on research publications acquired from the Scopus database (as of 14 December 2023). Future research should consider utilizing various databases like WoS and Google Scholar, as including additional databases could lead to diverse outcomes. Additionally, this review solely focuses on articles, with search terms restricted to English. Subsequent studies could overcome this constraint by broadening the scope to include other languages and forms of research, such as conference papers and books. Second, bibliometric analyses have limitations, such as being inherently reliant on large-scale data. Therefore, there may be exclusions for some relevant articles due to the absence of relevant keywords or when authors fail to include key terms in their keywords line [146]. Also, the bibliometric maps generated from analyzing the keyword network may encounter challenges in extracting comprehensive information from the data. To conduct a more thorough exploration, it is essential to incorporate additional details, such as complete texts, which would allow for a more comprehensive examination. In addition, the outcome of subjectivity is the establishment of a threshold level for the visibility of keywords in VOS viewer. This threshold is set based on the most cited or frequently occurring articles and keywords, potentially excluding some relevant articles with fewer citations. Researchers determine these threshold levels based on their judgment, as they serve as the default setting for VOS viewer [147]. Moreover, a limitation of bibliometric analysis is its exclusive focus on quantitative metrics, which may not always accurately evaluate recently published articles that have not yet received a large number of citations [148]. Recently, various bibliometric analysis software tools like “SciMAT software” have been developed, which future studies can leverage. Third, our findings could be impacted by our review of the literature and our categorization into various clusters and themes. Despite our efforts to maintain objectivity and coherence, it is possible that other authors and researchers might have different interpretations or classifications of the publications. Although we used bibliometric analysis to provide an overview of the current literature discussing the impact of ESG on firm value; however, it should be noted that the term CSR has been somewhat combined with ESG as ESG is part of the elements of corporate social responsibility [51]. As a result, this may not fully capture the scope of the field regarding the impact of ESG disclosures on firm value. Future work could complement this review’s findings by discussing ESG separately from CSR through meta-analytical review or content analysis to offer a more comprehensive understanding of this topic. Despite these constraints, we maintain that our research offers valuable insights into primary factors and possible paths for future exploration in this field of study, which could greatly aid in comprehending and improving practices concerning the influence of ESG on company value. Given the interdisciplinary nature of ESG disclosures, future studies could integrate the literature from related fields such as finance and environmental information disclosure. Therefore, this bibliometric review offers a thorough analysis of the influence of ESG disclosure on firm value research, uncovering diverse aspects, including geographical distribution, influential shareholders, and prevalent and emerging themes. An analysis of these findings highlights their importance for academic researchers, investors, and policymakers, which may contribute significantly to the evolution of this research field. Therefore, identifying prevailing, emerging, and future research directions that can be further developed in this field. This review is a crucial step in identifying the factors that enhance firm value.