This paper studies how the strength of social ties are affected by the geographical location of other individuals and their social capital. We characterize the equilibrium in terms of both social interactions and social capital. We show that lower travel costs increase not only the interaction...

This paper presents a new theory of crime where leaders transmit a crime technology and act as a role model for other criminals. We show that, in equilibrium, an individual's crime effort and criminal decisions depend on the geodesic distance to the leader in his or her network of social...

We randomly assigned 115 primary schools in Bangladesh to one of two settings: children studying in groups with friends and children studying in groups with peers. The groups consisted of four people with similar average cognitive abilities and household characteristics. While the achievement of...