SYSTEMATIC REVIEW OF SUSTAINABLE CORPORATE GOVERNANCE OF SMEs: CONCEPTUALISATION AND PROPOSITIONS

Systematic review of sustainable corporate governance of SMEs: Conceptualisation and propositions. the of However, few studies exist on the incorporation of sustainability principles into the corporate governance practices of small and medium-sized enterprises (SMEs). This study aims to review the current state of the literature on the incorporation of sustainability principles in corporate governance practices of SMEs, validate the outcomes and set future research agenda. This research was conducted using a systematic literature review (SLR). Findings suggest female executives, board size, firm size, board diversity, board independence and ownership concentration are the dominant themes in sustainable corporate governance (SCG) of small businesses. Studies are predominately conducted in the European context with some studies in Asia and North America while studies in Africa and South America are limited. The study showed that corporate governance models of SMEs have excluded pertinent issues such as climate change, digitization, and racial equality. Although the study concentrated on limited but highly relevant literature, the results establish the basis for further studies and enhance debates on sustainable models for corporate governance practices of SMEs. Compared to existing studies, the outcomes of this study emphasise the need to prioritise sustainability-inspired research of SMEs and provide solutions to integrate sustainable practices in small businesses. The study offers a guiding framework for managers and policy makers to promote progressive and sustainable practices in managing SMEs. Declaration of conflicting interests: The Authors declare that there is no conflict of interest.

However, few studies exist on the incorporation of sustainability principles into the corporate governance practices of small and medium-sized enterprises (SMEs). This study aims to review the current state of the literature on the incorporation of sustainability principles in corporate governance practices of SMEs, validate the outcomes and set future research agenda. This research was conducted using a systematic literature review (SLR). Findings suggest female executives, board size, firm size, board diversity, board independence and ownership concentration are the dominant themes in sustainable corporate governance (SCG) of small businesses. Studies are predominately conducted in the European context with some studies in Asia and North America while studies in Africa and South America are limited. The study showed that corporate governance models of SMEs have excluded pertinent issues such as climate change, digitization, and racial equality. Although the study concentrated on limited but highly relevant literature, the results establish the basis for further studies and enhance debates on sustainable models for corporate governance practices of SMEs. Compared to existing studies, the outcomes of this study emphasise the need to prioritise sustainability-inspired research of SMEs and provide solutions to integrate sustainable practices in small businesses. The study offers a guiding framework for managers and policy makers to promote progressive and sustainable practices in managing SMEs.  Opute, 2020). This emergence of sustainable corporate governance is not only beneficial to small enterprises, but its trickling-down effects are pertinent to all connected stakeholders of the small business. According to a report from the Westpac Bank in collaboration with Deloitte, 30-40 percent of the growth and successes of small firms can be attributed to the operation of wellstructured sustainable governance systems (Westpac, 2019). Scholarly literature supports the critical role sustainable corporate governance plays in the overall success of small businesses (Jiujin, Gupta, Haihong, & Qiang, 2020; Shehata, Salhin, & El-Helaly, 2017). Moreover, the literature reveals the effects of improvement of sustainability in corporate governance on the financial success of small enterprises in the areas of profitability, risk management, innovation, family business, environmental protection, and diversity (Charas & Perelli, 2013;Chatterjee & Bhattacharjee, 2021).
Despite the numerous studies on the essence of corporate governance in small firms, a limitation of the literature is a sparse analysis and synthesisation of common themes in adopting sustainability practices in governing the firms. Previous studies provide few investigations into the dominant and revolving issues in the literature about sustainable corporate governance of small businesses ( Torchia & Calabrò, 2016). Furthermore, studies on sustainable corporate governance have largely used big profit-making organisations in their analysis with little attention to small businesses (Ndubisi, Zhai, & Lai, 2021). Two reasons could be suggested for this phenomenon. First, it is difficult to access data on the activities of many small businesses including the sustainable corporate governance structures of the firm (Li, Terjesen, & Umans, 2020). Second, the majority of small businesses are owned and run by individuals who are the embodiment of the businesses which makes it difficult to embed sustainable practices which are against the owner's personal principles and beliefs (Hansson, Liljeblom, & Martikainen, 2011). Business activities are centered on the individual owners; thus, laying down the sound and sustainable corporate governance structures is rare (Arora & Singh, 2020). Studies on sustainable corporate governance of small businesses appear fragmented with limited theoretical underpinnings. This leaves studies and results dispersed and scholars unable to conceptualise a common direction to address the sustainable problems faced within the corporate governance structures of small businesses. For instance, many studies have been conducted on small and medium-sized enterprises (SMEs), while some replicate themselves, others seem not to inform new knowledge or clear research direction (Esteban-Salvador & Gargallo-Castel, 2019; Shehata et al., 2017;Elmagrhi et al., 2017). Therefore, the main aim of this study is to conceptualise and propose the integration of sustainability practices into the corporate governance of SMEs and to inform future research direction. Specifically The scholarly relevance of this study is mainly twofold. First, the results of this study contribute to the academic debates and solutions to integrate sustainable practices into the corporate governance of small businesses. The study highlights the most pressing and trending sustainable issues that need to be investigated which existing literature has either been avoided or paid little attention to. From this study, theoretical models could be developed by researchers to support business owners to recognise pertinent issues such as inclusion and diversity, climate change and circular economy in governance systems of SMEs. Second, the study provides a practical guide for small business owners to channel resources to critical areas that need continuous improvement to contribute to United Nations Sustainable Development Goals (SDGs).
The remaining sections of the paper continue as follows. Section 2 presents the systematic method for the retrieval and selection of relevant publications for this study. Also, the techniques to extract and interpret the selected articles are explained in this section. In Section 3, the results of the thorough analysis of the studies are shown with discussions drawing lessons and empirical support from literature and published documents. Section 4 presents the discussions of the study, Section 5 is devoted to research gaps, and recommendations for future research and practice, Section 6 concludes the study.  (Khongmalai, Tang, & Siengthai, 2010). It is argued that small businesses should not only exist for profit maximization of the owners but responsive and long-term measures to satisfy the needs of the larger society and the environment must be incorporated into the management of the business. Small businesses should routinise and embrace sustainability principles into the corporate governance framework in transitioning into meeting climate agreements and sustainable goals.

METHODOLOGY
In this study, four-stage systematic literature review (SLR) and validation methodology were utilised to retrieve and analyse existing studies on sustainable corporate governance of small businesses. The stages have been outlined as follows in Figure 1. The search for articles was conducted in the Scopus database. Scopus is highly recognised and contains a broad range and large quantity of research articles covering diverse academic subjects and research interests (Almaqtari, Al-Hattami, Al-Nuzaili, & Al-Bukhrani, 2020; Li et al., 2020). Also, Scopus' search engine provides researchers with a wide range of current, reliable, readable and relevant search options of studies on corporate governance of small businesses (Farah, Elias, Aguilera, & Abi Saad, 2021). The search for articles was done with keywords of -sustainable corporate governance‖ or -sustainability in corporate governance‖ or -corporate disclosures‖ and -small business‖ or -small and medium scale business‖ or -small and medium-sized enterprises‖ or -SMEs‖ or -SME‖ or -small enterprises‖ or -small and medium-sized enterprises governance‖ or -SME governance‖.
Additionally, the search was broadened to cover key terms on corporate governance such as -board size‖ or -board structure‖ or -board diversity‖ or -CEO tenure‖ or -CEO duality‖. Initially, the search results produced 245 documents. The search outcomes were limited by language (English) but the publication period (years) was unlimited till 2020. Finally, the document type was restricted to -articles‖ and source type to -journal‖. The filtered search articles came down to 174 articles which we downloaded for further analysis.

Stage 2 -Selection of relevant articles
The main criterion for the selection and rejection of articles from the 174 studies retrieved was to identify those papers which are directly aligned with this study's objectives set in the introduction section.
The authors read and assessed the 174 papers in line with the objectives of the study to select the relevant papers. Studies that mentioned some of the keywords but did not delve deeply into the topic of sustainable corporate governance of small businesses were excluded. Moreover, studies that underwent less strenuous peer-review in well-known publishers such as Emerald, Wiley, ScienceDirect (Elsevier), Taylor

Stage 3 -Qualitative content analysis (QCA)
This phase concentrated on the analysis of the selected 57 articles selected in stage two. The authors read all the 57 selected articles thoroughly and manually without the aid of any software. During the reading stage, relevant statements, variables, texts, words and phrases were extracted from the articles. These items identified were coded according to the patterns of messages of the appearance of the items and the common features the items share together. The codes were reviewed and refined leading to the formation of dominant themes. The dominant themes identified through the analysis were grouped and discussed to address the research objectives.

. Geographical distribution of publications
In assessing the key origins of the studies on SCG of small businesses, it was discovered that many of the studies were undertaken in Europe. Countries such as the United Kingdom reported 10 published studies on the topic followed by Italy and Spain with 9 and 8 articles respectively. In addition, European countries such as Finland (2 articles), Norway (2 articles), Greece (1 article), Denmark (1 article), Sweden (1 article), Estonia (1 article) and Belgium (1 article) have contributed to the growing number of research on sustainable corporate governance to ensure business continuity and meet the United Nations SDGs. Consequently, Europe having 65 percent (37/57 articles) of the research on this topic is an indication of the commitment to strong systems to boost small and emerging enterprises. Also, in Figure 3, Asia came second as the continent researching this topic. India, China and Indonesia in the Asia sub-region reported 3 articles, 3 articles and 2 articles respectively. South America and Africa produced 4 articles each; these came from countries including Ghana (3), South Africa (1), Brazil (2) and Argentina (2). The North American sub-region represented by the United States posted 2 articles while Australia and the Pacific Islands had none.

Journals of selected articles
In all, the 57 articles were published in 46 peerreviewed journals. Most of the journals published one (1) article while few journals published two (2) or more articles on this topic. Six was the highest number of articles published by a journal followed by four, three and two respectively. The top publishing journals include Corporate Governance and Journal of Small Business and Enterprise Development. This implies that they were the journals that contributed the most to this topic. In Table 1 we have shown the eight (8)

Theories, research methods and summary of findings from selected articles
Upon critical analysis of the selected articles, three other issues are presented in Table 2 relating to the theories used in the studies, research methods, and key results or conclusions from the 57 studies. Quantitative techniques ranked prominently and were used in 49 of the articles representing purely mathematical models based on surveys and interviews. Agency theory underpins most of the studies under review with key findings advocating for the empowerment of women, diversity, and climate change matters to be addressed. Results show a negative association between gender, age diversity and the performance of small firms. 9 Briozzo, Albanese, and Santolíquido (2017) N/A Quantitative: Bivariate analysis with a sample size of 22 The outcome shows a significant relationship between the participation of women in both ownership & external audit and the financing decision of firms. 10 Al-Najjar and Al-Najjar   35 Machold, Huse, Minichilli, and Nordqvist (2011) Team production theory Hypotheses tested through survey data in Norway The study reveals that board members' knowledge had a significant impact on board strategy involvement and diversity. 36 Rachagan and Satkunasingam (2009) Agency theory A case analysis of existing laws governing small firms in Malaysia The structure of ownership of SMEs in Malaysia, like many other emerging economies, reflected concentrated shareholder ownership resulting in rising agency costs due to the high possibility of misappropriation by most shareholders. 37 Hung and Chen (2009) Stewardship and agency theory Quantitative approach The study showed that board ownership was higher in Taiwan (23%) than in the US or the UK. 38 Michelman (2009) Culture and agency theories Quantitative method The paper exposed the interplay between a country's governance and corporate governance and how this interplay was critical for the success of small firms in Latin America.  43 Abor and Biekpe (2007) Agency, resource dependency and stewardship theories Regression analysis using data from 120 small firms Corporate governance could greatly assist the SME sector by infusing better management practices, stronger internal auditing, and greater opportunities for growth for SMEs in Ghana. 44 Abor and Adjasi (2007) Stakeholder, institutional and agency theories  50 Ritchie and Richardson 4-quadrant ideal model Qualitative approach The results indicated that a perennial object for reformers, the whole concept of governance, stood invigorated, giving particular impetus to corporate governance and its reform for small firms. 51 Hamidi and Machold (2020)

Agency and stakeholder theories
Qualitative content analysis The study proposed novel ways in which boards can become integral to firms' value creation processes through ownership and diversity on the board. The empirical results show that price/earning investment can raise the firm value as well as affect management behaviour at the macro level.  54 Gangi, Meles, Monferrà, and Mustilli (2020) Stakeholder theory and conflict resolution model The paper used a sample of 2480 firms from 51 countries covering the period 2010-2015 with a Z-score model for the analysis The results revealed that small firms with more effective corporate governance mechanisms were more likely to be more engaged in corporate social responsibility activities. The study proposed an original structural model that analysed the relationship between sustainable firm performance, and a board of directors' external and internal social capital. 56 Chatterjee and Bhattacharjee (2021) Resource-based theory and agency theory Quantitative method: Crosssectional data of 264 Indian technology SMEs The study found support for the individual influence of research and development on the intensity of the performance of SMEs. 57 Uhlaner, de Massis, Jorissen, and Du (2020) Dependence, agency, and resource-based theories Quantitative method using data from a sample of 561 Belgian SMEs The results revealed that family ownership control and infrequent board meetings were two important contingencies that reduced management's propensity to disclose firm-specific information to the board in the presence of outside directors.

Dominant themes in sustainable corporate governance (SCG) of small businesses
The dominant themes identified in SCG mechanisms were examined with respect to three firm-specific factors shown in Table 3. Six dominant themes were identified under SCG; these are female executives, ownership concentration, firm size, board size, board diversity and board independence. Three dominant firm-specific factors were identified as performance, asset, and risk.

Firm-specific factor (sub-constructs) Reference Conclusions/Operationalisation
Female executive

Firm-specific factor (sub-constructs) Reference Conclusions/Operationalisation
Board size

Female executive
Results of the empirical study provide evidence of the effect of decision-making on female-dominated bodies in small businesses (Esteban-Salvador & Gargallo-Castel, 2019). This goes further to illustrate the importance of corporate governance for certain aspects of small businesses. Membership of females in executive governance cadres of small businesses was predominantly discussed relative to performance, assets, and risk exposure of small businesses as shown in the above Table 3. The results of these firm-specific factors are mixed. Findings show that women's participation as members of the executive cadre influences the performance of an SME and improves its assets which goes further to have implications on its ownership structure, external audit, and financing decisions (Briozzo et al., 2017;Westpac, 2019). The findings of this research gave evidence that firms with executive women would most likely engage in export or comparatively have a high volume of export, and that women would likely be more cautious as well as prudent as owners (Berenguer et al., 2016). Kengne (2016) showed that small businesses owned by men and women performed relatively better than those exclusively owned by men but did not show that the presence of women alone resulted in increased performance of the firm. Nieto (2006) found evidence that internationalisation was negatively related to family ownership and that corporate block holders in family firms encouraged internationalisation. Chen et al. (2014) further showed that potential agency benefits of family ownership (e.g., altruism, information advantage, and alignment of interest) were more likely to be realised in internationalisation of small firms. Additionally, they argued that small businesses with high family ownership are more likely to build a portfolio of strategic resources and capabilities that favour internationalization. They also provided evidence that the interaction of family ownership with institutional ownership was significantly positive, suggesting that the size of shareholdings by institutional investors may alter the degree of family influence on SME internationalization.

Firm size
Firm size is also associated with mixed results. Süsi and Lukason (2019) showed that failure risk is not associated with how big a small business is, while Li et al. (2016) suggested that firm size is positively associated with operating lease share. This presupposes that capital lease share increases with firm size. In addition, Charas and Perelli (2013) showed that both high and low governance rated small firms had differences between norms and behaviours corresponding to two distinct areas in which they perceived performance. The findings revealed that the effect of this corporate governance mechanism on performance and risk exposure was positive. Al-Najjar and Al-Najjar (2017) and Jiujin et al. (2020) also examined the impact of external financing on firm values and SCG. They found that external financing needs had a positive relationship with the value of firms as a proportion of their size. They went further to show that big and small businesses coupled with those with low debt profiles had a better corporate governance structure. SCG played a partial and mediating role in the relationship between private equity investment and the value of a firm. showed evidence that board size was associated with performance. The mixed result has an implication for the research gap to be discussed later in the research. There is also strong evidence that board size plays a significant role in determining the capital structure of small businesses which enhances their performance (Dasilas & Papasyriopoulos, 2015). Results show that board size also has a significant influence on the level of dividend payout (Elmagrhi et al., 2017).

Board diversity
The differences (in terms of age, size, race, culture, experience, orientation, etc.) between people who constitute the members of the board also play a role in small businesses. Findings from Shehata et al.
(2017) reveal a negative association between board diversity and the performance of small firms while Elmagrhi et al. (2017) revealed a significant relationship with the level of dividend payout. The diversity of the members of the board is expected to affect the operation of small businesses in different ways such as exposure and skills needed to run a business. If the skills of the board in managing a business are poor, it will negatively affect the SME and vice versa. It is pertinent to state that the knowledge of board members has a significant influence on strategies that small businesses apply in the running of the business (Machold et al., 2011). Board leaders' efficacy is a function of constructive team output in the boardroom. Findings from Machold et al. (2011) show that the importance of the chairperson's leadership efficacy for board strategy involvement was more evident when considering firms with CEO duality. Boxer et al. (2012) examined the differing perception of non-executive directors' role in small firms in the UK and observed that patterns of trust between directors changed over time and actual board behaviour was perceived differently by members based on their diversity.

Board independence
The independence of the members of the board of directors also plays a significant role in small businesses concerning decision-making. As the highest decision-making body of the firm, it is expected to be strategic and contribute significantly to the success or otherwise of small firms. An examination of SCG effect on performance by Shapiro et al. (2015) and Kyereboah-Coleman and Amidu (2008) revealed that having independent members of the board of directors coupled with the presence of an external CEO positively affected the performance of SMEs as well as their asset portfolios. At the same time, there is some evidence that having independent members of the board and the presence of an external CEO positively affect invention patents granted to small firms. Shapiro et al. (2015) and Kyereboah-Coleman and Amidu (2008) further show that board independence has a positive effect on the risk exposure of SMEs. Evidence suggests that the more the members of the board are not influenced by external factors such as family relations, the more the chances of making a decision that will enhance the growth of the small firms (Arora & Singh, 2020).

Conceptual framework and propositions
Previous studies on corporate governance structures of CEO characteristics in small businesses have largely been explained by the upper echelons' theory (see Figure 4). In this view, Yasser, Al Mamun, and Ahmed (2017) posited that upper echelons theory suggests top executives' characteristics impact cognitive processes, which affect the strategic growth of small firms. Studies using upper echelons theory have argued that to understand organisational decisions and outcomes, it is important to identify the individuals behind these decisions (Aguilera & Jackson, 2003; Attah-Boakye, Adams, Kimani, & Ullah, 2020). This is due to the influences they exert based on their experience, values, and cognitive lenses. Although prior studies have indicated the theory's strength in explaining managerial decisions and outcomes, others have expressed some concerns about the theory's coverage. For instance, in Buniamin, Johari, Abd Rahman, and Rauf (2012) paper, the authors explained that the upper echelons provide an understanding of the role of CEO based on leadership qualities and behaviour. The study stated that one of the theory's limitations is its inability to explain how an individual's power can affect top management characteristics and organisational outcomes. . This is because organisational survival strongly depends on how to align the interest of owners (principals) and that of managers (agents) to overcome the agency problem (de Villiers & Dimes, 2021). In this regard, agency theory emphasises the relationship that arises when the owners (principals) hire managers (agents) to be responsible for organisational decision-making (Boadi & Osarfo, 2019). The agency problem emerges when principals and agents hold differing interests in the organisational activities on the diversity and operationalisation of the systems in the organisation. Aguilera and Jackson (2003) argued that the agency problem may lead to divergent goals and risk preferences and affect managerial actions and strategic choices. The principal-agent hierarchy clearly defines corporate governance mechanism with separate roles and responsibilities to tackle problems. Specifically, the owners have the mandate to choose the board of directors who would in turn undertake the monitoring responsibilities on behalf of the principals (Goyal et al., 2019). This implies control over the management and strategy of the small business. This includes the appointment of the managers as well as evaluating the performance of the management team. Additionally, it is important to impose internal controls to restrain the agent's self-centred behaviour (Attah-Boakye et al., 2020). Since imposing the internal controls comes with sanctions, it will minimize the agency problem. Second, family ownership augments corporate governance leading to a significant reduction of the ownership-agency problem because their interests may be aligned (Pucheta-Martínez, Bel-Oms, & Olcina-Sempere, 2018). This implies that the ownership concentration ordinarily affects the common interest shared among stakeholders to serve as a boost for the corporation. Consequently, we hypothesise that: H3: Ownership concentration positively influences the sustainable growth of small businesses.
H4: Board size negatively influences sustainable growth of small businesses.
In addition, agency theorists have argued that the presence of external corporate governance mechanisms may influence the size of the board of directors of a small business. This implies the small firms working in line with the regulators' requirements for fair presentation. It ensures the interest of owners is safeguarded. Also, Boxer et al. (2012) argue that another limitation of agency theory is the assumption that there exists one type of fiduciary relationship, characterized by divergent interests between principal and agent which can be brought together by control mechanisms (internal and external) and through economic incentive plans. Ciampi (2015) believes that the focus should not only be on the principal and agent relationship. Even though agency theory has been developed mostly in the context of structured organisations such as firms trading publicly where managers may have limited stake, its logic has the potential of explaining the governance relationship in small firms. Stewardship theory assumes that CEOs identify with the mission of their organization and are intrinsically motivated to pursue organizational goals. Also, from a socio-psychological perspective stewardship exists where the firms' members are driven by collectivist mentality other than self-interest.
Such firms value cooperative behaviours more than self-interested behaviours (Kot, 2018). Elmagrhi et al. (2017) further argue that a key limitation to the agency theory is the separation of CEO and chairmanship role. They believe that separating the CEO and chairman roles may prevent unity and efficiency in organisational decisionmaking. As such, sharing a common organisational mission requires unity among the top-level management.
One strength identified with stakeholder theory is that board members including CEOs often see themselves as stewards which gives them a strong sense of organizational identity (Li et al., 2020). Possessing this strong identity inclines them to achieve the organisational goals, not personal interests. These studies conclude that CEOs with superior power will advance the interests of the firm and its shareholders (Torchia & Calabrò, 2016

RESEARCH GAPS AND RECOMMENDATIONS
The studies reviewed have limitations, and thereby provide opportunities for further research, improved practices, and policies on corporate governance. These gaps are categorised into four.

Diversity policies in small businesses
The interactions between the position of women, culture and employees from different backgrounds in small firms have received less attention in practice and among the research community (Kussudyarsana et al., 2020). A series of studies captured a particular culture at the expense of others with little interaction between cultural variables and the position of women in a family business in the governance structures of small businesses (Chen et al., 2014). Cultural dissimilarity may significantly affect ownership by women and minority groups in a dominant culture which influences and consequently, drives business activities. Gnan et al. (2015) mentioned that the composition of the governance structure of small family firms is not disclosed and examined, leading to a limited understanding of the make-up of the top hierarchy of the governance councils. Does the involvement of women and people of different cultures lead firms to take different decisions and ensure superior performance of small enterprises? These issues must be analysed in the context of religion, trust, and other macro-factors such as legal framework and entrance barriers on the governance structures of small firms (Lopez-Perez & Rodriguez-Ariza, 2013). Also, it is recommended that research on ownership and governance of small firms shared equally between men and women will be more robust and insightful. Moreover, an analysis of studies and proposition of laws regarding the different behaviours of the roles of women, i.e., owner, board members and managerial positions, could give better understanding of diversity in small businesses.

Big data and record-keeping
The selected articles on which this study focussed were based on relatively small samples of data on sustainable corporate governance relating to small businesses. Most of the sampled firms are young and small according to most of the studies, making it difficult to extract a time series and long-run data on the activities of corporate governance of small firms (Al-Najjar, 2018). The lack of extensive information about the profile of owners, remuneration of women managers, age or previous work experience, is troubling (Esteban-Salvador & Gargallo-Castel, 2019). The available data on small businesses suffer from common method bias and external validity. A database of governance structures of small firms must consider the interplay between the main constructs and established methodological underpinnings. Also, it is suggested that future researchers use data from more companies to provide more meaningful insights. This study can also be extended to find out associations between corporate governance attributes and short-run and long-run performance of listed small firms. The data must also capture all members of a board, not a handful of them, to facilitate comparison and contraction of data sourced from multiple firm directors and board members.

Climate change and green business models
The studies existing on the traditional model of corporate governance structures of small firms emphasise little on climate action, net zero-emission targets and green business models (La Rosa & Bernini, 2018). As a growing research area of interest to business owners and policymakers, it will be interesting for future studies to combine constructs on sustainability to assess the sustainable growth of small businesses.

Transparency and accountability
The increased interest in the role of transparency and accountability in how the governance of small businesses impacts the environment and social issues must spark further research, together with a change in policy directions (Hamidi & Machold, 2020). Large corporations are more prone to enhanced reporting activities than small and medium scale enterprises, leading to undisclosed and unaddressed matters concerning the board's social capital, its effectiveness, and sustainable benefits; these are dynamic constructs that should be analysed over time. Therefore, future studies should seek to capture those constructs longitudinally. In addition, Kyereboah-Coleman and Amidu (2008) stated that failures to draw the attention of institutional investors to corporate transparency and governance mechanisms must be countered with the presence of more non-executive directors. These mechanisms ensure adherence to environmental and social codes and regulations. Increasing disclosure volume may remedy declining investor interest in small businesses.

CONCLUSION
In this study, a systematic literature review methodology was used to assess peer-reviewed publications to ascertain the state of integration of sustainability into the corporate governance of SMEs. The dominant outcomes of the study show that existing studies on corporate governance of SMEs have mainly focused on six topical issues, namely: board size, board diversity, board independence, female executive, ownership concentration and firm size. Further, the study demonstrates relevant and critical issues that need to be integrated into the corporate governance of SMEs which have been neglected or received little attention. These issues include climate change, diversity and inclusion policies, transparency and accountability, and robust record-keeping of information on the activities of SMEs. It was observed that these challenges are more prevalent in emerging economies where an individual who embodies all the activities of the business dominates SMEs. It is important that SMEs embraces diversity policies that encourage more female to own businesses and decry misogynistic practices at workplaces. In addition, the growth of small businesses in this era and future have been tied to the usage of IT-aided tools and techniques. Therefore, SMEs are encouraged to take advantage of technological advancements to boost the performance and growth of activities.
Theoretically, the results of this study imply that the scientific research community must devote more research to the sustainability of corporate governance of SMEs. This study provides the key outcomes as the starting point to do further studies. In corporate practice, the findings of the study provide small business owners with insights to integrate sustainable practices into the governance systems of their businesses. Policymakers and regulators will gain insight into the relevant policies to formulate to guide SMEs around the world in achieving global sustainable goals. internationalization. Journal of World Business, 51 (