There is an increasing focus on gender diversity on executive boards. While the share of female employment in large firms has increased dramatically in the United States and the European Union, this has not been reflected in the gender composition of executive boards (Black and Juhn, 2000; Bertrand and Hallock, 2001). Growing concerns about gender equality have led to a large number of regulations across the world that aim to increase female representation on corporate boards. Board gender diversity has also become an important criterion for institutional investment and listings by such socially responsible indices as the FTSE4Good Index and the Domini 400 Social Index (Adams and Ferreira, 2009). Proposals to increase the proportion of female directors are premised upon the idea that this will be beneficial for governance, and ultimately, firm performance. A complication with these initiatives is that the focus on representation may miss the actual integration of female directors into firm governance. This is, perhaps, reflected in the lack of consistent evidence on the performance-impact of female representation on corporate boards. The economic implications of board gender diversity may be ambiguous if decisions to increase female representation on boards are, in part, driven by social and political pressures that raise concerns regarding token representation. For instance, using a sample of US firms, Adams and Ferreira (2009) in fact find a negative impact of having females on the board on firm performance, despite better attendance records and more effective monitoring in firms with more gender-balanced boards. While for the UK, Gregory-Smith, Main and O’Reilly (2014) find no evidence that the gender composition of the board affects firm performance. Whilst the effect on the firm performance of board gender diversity has been extensively researched, recent work highlights the importance of board committees in the functioning of the board (Adams, 2003; Adams, Hermalin and Weisbach, 20010; Guo and Masulis, 2015). This is important because boards do most of their work through committees, and we know much less about how committee composition affects performance than we know about the effects of board composition. Female representation on committees is likely to be a more effective measure of board gender diversity, and likely to have a more direct effect on firm performance. While regulatory and institutional pressures may lead to the appointment of female directors on the board, they do not ensure the participation of appointed female directors in the governance mechanism. Therefore, appointment to committees reflects integration of female directors in the governance mechanism. Diverse boards can benefit from better matching of skills to functions, and appointment of female directors to decision-making committees can be a source of competitive advantage.