A great deal of urban policy depends on the possibility of creating stable, economically and racially mixed neighborhoods. Many social interaction models - including the seminal Schelling (1971) model -- have the feature that the only stable equilibria are fully segregated. These models suggest...

There is a wealth of research in psychology demonstrating that agents process information with the aid of categories. In this paper we study this phenomenon in two parts. First, we build a model of how experiences are sorted into categories and how categorization affects decision making. Second,...

We study social interactions in the risky behavior of best-friend pairs in the National Longitudinal Study of Adolescent Health (Add Health). Focusing on friends who had not yet initiated a particular behavior (sex, smoking, marijuana use, truancy) by the first wave of the survey, we estimate...

We examine friendships and study partnerships among university students over several years. At the aggregate level, connections increase over time, but homophily on gender and ethnicity is relatively constant across time, university residences, and different network layers. At the individual...