CEO social capital, board gender diversity and environmental disclosures of public companies in Southeast Asia

Purpose We examine the relationship between CEO social capital and environmental disclosures and the moderating role of board gender diversity on the basis of stakeholder theory. Design/methodology/approach We use 937 firm-year observations from public companies, excluding the financial sector, in Indonesia, Malaysia, Singapore and Thailand for the 2017–2023 period. A fixed-effects regression model is used as the primary model and robustness tests, such as dynamic panel entropy balancing, propensity score matching and selection bias tests, are conducted to address endogeneity. Findings The results indicate that CEO social capital improves environmental disclosure practices. However, board gender diversity weakens this relationship, indicating that more gender-diverse boards tend to have lower levels of environmental transparency. Path analysis confirms that CEO social capital increases firm value through a complex mediating mechanism involving gender diversity and environmental disclosures. Practical implications This study emphasises that CEO social capital is a strategic asset that strengthens environmental transparency and legitimacy. Companies are advised to evaluate the professional networks, social reputation and external engagement of CEO candidates during the recruitment process and strengthen social capacity through cross-sector collaboration and sustainability forums. Originality/value This study addresses the gap in the literature by demonstrating how CEO social networks and gender diversity simultaneously influence sustainable governance in developing countries.