Companies pondering the incentives for increased gender diversity in their executive ranks may need to look no further than the bottom line.

Having women in the highest corporate offices is correlated with increased profitability, according to a new study of nearly 22,000 publicly traded companies in 91 countries.

The study, released Monday by the Peterson Institute for International Economics, a nonprofit group based in Washington, and EY, the audit firm formerly known as Ernst & Young, found that despite the apparent economic benefits, many corporations are lacking in gender diversity.

Almost 60 percent of the companies reviewed had no female board members, and more than 50 percent had no female executives. Just under 5 percent had a female chief executive.