This executive summary on JPAL describes an article by Raghabendra Chattopadhyay and Esther Duflo in which they examined what happened to local spending in 1993 in villages in India, when a law changed to make one third of seats for village leaders reserved for women.
The researchers found that when the women held positions of greater power, they tended to spend more time and financial resources on improving the things that concerned them more than they concerned the men, including clean water and welfare programs.