Women, and particularly women in all-female groups, appear to be especially adept at providing public goods in developing countries. We use a one-shot Public Goods game to explore the effect of sex and a group's sex composition on the voluntary provision of public goods in a Nairobi slum. Sex heterogeneity hurts the voluntary provision of public goods because women—but not men—contribute less in mixed-sex than same-sex groups. Women contribute as much as men in same-sex groups. This result is driven by women's pessimism and men's optimism about others’ contributions in mixed-sex groups rather than by gendered social preferences.
We examine a new intervention to overcome gender biases in hiring, promotion, and job assignments: an “evaluation nudge,” in which people are evaluated jointly rather than separately regarding their future performance. Evaluators are more likely to focus on individual performance in joint than in separate evaluation and on group stereotypes in separate than in joint evaluation, making joint evaluation the money-maximizing evaluation procedure. Our findings are compatible with a behavioral model of information processing and with the System 1/System 2 distinction in behavioral decision research where people have two distinct modes of thinking that are activated under certain conditions.