In fact, many companies experience stock price declines when women are added to the board of directors, Bloomberg points out.

An analysis of 14 years of market returns across almost 1,900 companies recently revealed that when companies appoint female directors, they experienced two years of stock declines. Companies saw their stock fall by an average of 2.3% just from adding one additional woman to their board.

Kaisa Snellman, an assistant professor of organizational behavior at INSEAD business school and a co-author of the study said: "Shareholders penalize these companies, despite the fact that increased gender diversity doesn't have a material effect on a company's return on assets. Nothing happens to the actual value of the companies. It's just the perceptions that change."