Homophily, the tendency of linked agents to have similar characteristics, is an important feature of social networks. We present a new model of network formation that allows the linking process to depend on individuals types and study the impact of such a bias on the network structure. Our main...

This study explores the formation of buyer-seller relationships in markets with observable quality. We develop a model that explains why relationships form in equilibrium within such markets. A key feature of our model is that as individuals gain experience in the marketplace, they resolve...

This paper studies the dynamics of fundamental research. We develop a simple model where researchers allocate their effort between improving existing fields and inventing new ones. A key assumption is that scientists derive utility from recognition from other scientists. We show that the economy...

We introduce uncertainty and risk aversion to the study of international environmental agreements. We consider a simple model with identical agents and linear payoffs. We show that a stable treaty with positive action always exists. While uncertainty lowers the actions of signatories, we find...

We provide new results regarding the identification of peer effects. We consider an extended version of the linear-in-means model where each individual has his own specific reference group. Interactions are thus structured through a social network. We assume that correlated unobservables are...

This paper brings a general network analysis to a wide class of economic games. A network, or interaction matrix, tells who directly interacts with whom. A major challenge is determining how network structure shapes overall outcomes. We have a striking result. Equilibrium conditions depend on a...