Social scientists are increasingly engaging in experimental research projects of importance for public policy in developing areas. While this research holds the possibility of producing major social benefits, it may also involve manipulating populations, often without consent, sometimes with...

We examine a public goods game in 83 communities in northern Liberia. Women contributed substantially more to a small-scale development project when playing with other women than in mixed-gender groups, where they contributed at about the same levels as men. We try to explain this composition...