Abstract: Prior literature shows that mandatory gender quotas are detrimental to firm value. However, little is known about causal effects of voluntarily appointed women. A large board dataset covering 53 countries and about 500,000 people enables us to identify exogenous retirements of board members due to death or illness. Long and short-run event studies yield evidence for a positive valuation effect of women. This is confirmed in panel regressions for the entire dataset. This positive impact is not driven by women per se, but a glass ceiling effect due to more rigorous selection. Thus, firms can benefit from a corporate culture that fosters the promotion of women.
A working paper version can be found here: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2344786
The paper received a large press coverage. Some of it can be found here: http://www.manager-magazin.de/unternehmen/international/frauen-in-fuehrungspositionen-sind-gut-fuers-geschaeft-a-1061805.html
And here: http://www.faz.net/aktuell/beruf-chance/arbeitswelt/mehr-erfolg-wenn-die-chefin-stirbt-ist-der-schock-groesser-14101265.html