We randomly assign more than 6,000 students from 150 primary schools in Bangladesh to work on math assignments in one of three settings: individually, in groups with random schoolmates, or in groups with friends. The groups consist of four people and are balanced by average cognitive ability and...

'The economic importance of social interactions not mediated by the market has long been recognized. However, it is only the emergence of network analysis that has supplied a useful method of study. The editors have performed a signal service by their anthology of important articles. They have...

We consider a model where each individual (or ethnic minority) is embedded in a network of relation-ships and decides whether or not she wants to be assimilated to the majority norm. Each individual wants her behavior to agree with her personal ideal action or norm but also wants her behavior to...

The aggregate economic impact of any developmental project depends on its effects within the chosen administrative region as well as its economic spillovers into other regions. However, little is known about how these spillovers propagate through geographic, ethnic and road networks. In this...