A growing body of research suggests that the composition of a firm’s board of directors can influence its environmental, social and governance (ESG) performance. In the banking industry, ESG performance has not yet been explored to discover how a critical mass of women on the board of directors affects performance. This paper seeks to fill this gap in the literature by testing the impact of a critical mass of female directors on ESG performance. Other board characteristics are accounted for: independence, size, frequency of meetings and Corporate Social Responsibility (CSR) committee. We use fixed effects panel regression models on a sample of 108 listed banks in Europe and the United States for the period 2011–2016. Our main empirical evidence shows that the relationship between women on the board of directors and a bank’s ESG performance is an inverted U-shape. Therefore, the critical mass theory for banks is not supported, confirming that only gender-balanced boards positively impact a bank’s performance for sustainability. There is a positive link between ESG performance and board size or the presence of a CSR committee, while it is negative with the share of independent directors. With this work, we stress the key role of corporate governance principles in banks’ ESG performance, with relevant implications for both banks and supervisory authorities.

Purpose: This study aims to examine the relationship between female directors and bank risk. In particular, whether such a relationship varies across sound or unsound banks and with or without a critical mass of female directors is tested. Design/methodology/approach: Using a sample of 215 listed banks from 40 countries over the period 2008–2016, this study carries out panel data analyses and tests all the model specifications on four different measures of risk (common equity ratio, leverage, NPLs ratio and price volatility). Findings: The findings show that increasing the number of female directors does not reduce bank risk when banks are unsound. When banks are sound, female directors have a significant and positive role in reducing risk, only until reaching a critical mass of women. Practical implications: This study provides useful corporate governance indications for policymakers and practitioners. Advantages of gender diversity on boards are recognized especially in sound banks, but increasing the number of women directors beyond the critical mass may not lead to lower risk. In fact, ethical or legal pressures aimed at increasing gender diversity on boards (i.e. soft or hard gender quotas) may cause undesired effects on bank risk, especially if female directors are not chosen on merit and skills. Moreover, gender-balanced boards, namely, with a “dual critical mass,” seem to assure more effective decision-making processes. Originality/value: This study provides empirical evidence on female board members and risk minimization, differentiating between sound or unsound banks. Furthermore, this study contributes to the literature on the critical mass of women on the board of directors by testing this theory for these two categories of banks.