Women remain underrepresented at all levels of corporate leadership, including among CEOs and board directors. Women make up 5% of CEOs in the Fortune 500, even less in the S&P 500. Women do slightly better on boards of directors—comprising about a fifth of board seats in large companies—but their numbers still do not reflect equality.

There is mounting pressure on companies to advance women leaders. But what difference does it make when companies appoint women to leadership roles?

We sought to answer this question using a unique data set of all Fortune 500 companies over a ten-year period, from 2001 to 2010. We were particularly interested in the impact of women’s leadership on a range of outcomes related to equality and diversity, corporate social responsibility, and product strength and development.

The results of our study are described in two papers, available here and here. We discovered that women leaders have broad and significant impacts on their companies. Companies with women in leadership roles, compared to those without, do better on every outcome. But women’s influence is contextual and dependent on their representation at different levels.

First, in terms of board composition, even a single woman director improves her firm’s performance in the areas of community engagement, governance and environmental sustainability. When three or more women serve on the board, the impacts are even stronger and extend to improved product development.

Second, we explored the impact of board composition for companies with women CEOs. We found that on their own, women CEOs advance their companies’ diversity policies and practices. And when women lead companies with influential women on their board, their companies do better than others in terms of governance, product strength, diversity and community engagement.

Finally, we found that women’s leadership on the board matters for companies led by men too. When women serve on the board, men CEOs are much more likely to champion stronger governance, community engagement and diversity. Without women on the board, men CEOs are less likely to be associated with any of these outcomes.

There are several implications of our findings for organizations.

First, board diversity matters irrespective of CEO gender. The weakest performers on every measure are organizations with men CEOs and all-male boards. Even a single woman on the board improves a firm’s commitment to social responsibility.

But the typical ‘one and done’ policy for women board directors is insufficient for advancing significant change. Women’s overall representation matters too. When women represent a critical mass of board directors (i.e., 3 or more), the firm’s record across a number of outcomes improves.

The message is clear: women leaders improve their companies’ records across a range of desirable outcomes. Companies serious about social responsibility, diversity and product development should recommit to board diversity and advancing women to top roles.


Alison Cook is a Professor in the Department of Management at the Jon M. Huntsman School of Business at Utah State University.

Christy Glass is a Professor of Sociology at Utah State University.