The fraction of women in economics has grown significantly over the last forty years. Yet, differences in research output between men and women remain large and persistent. These output differences are reflected in large network differences across the genders. Women have fewer collaborators, collaborate more often with the same coauthors, and a higher fraction of their coauthors are also coauthors of each other. Moreover, women coauthor a large share of their work and do so with more senior coauthors. Standard models of homophily and discrimination cannot account for these differences. We discuss how differences in risk aversion between men and women can explain them.