While the field of economics lacks diversity, there is little consensus on the underlying causes of or most effective solutions to this problem. The authors of this article combine data from the Integrated Postsecondary Education Data System (IPEDS) with data from their own survey of U.S. economics departments to identify institution and department characteristics associated with observed variation in gender and racial diversity of undergraduate students across departments. They focus their attention on student support, role modeling, course content, and the use of active learning pedagogy. While they find no significant associations between course content or student support with student diversity, they find that gender diversity in departmental faculty is a strong predictor and that active learning is positively associated with gender diversity.