Biographical note: Esther Mwangi is a scientist in the Forests and Governance Program of the Center for International Forestry Research, Bogor, Indonesia. Helen Markelova is a doctoral candidate in the Department of Applied Economics of the University of Minnesota, St. Paul. Ruth Meinzen-Dick is...

What makes diversity unifying in some settings but divisive in others? We examine how the mixing of ethnic groups in German schools affects intergroup cooperation and trust. We leverage the quasi-random assignment of students to classrooms within schools to obtain variation in the type of...