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 provide the first empirical application of a new approach proposed by Lee (2007) to estimate peer effects in a linear-in-means model. This approach allows to control for group-level unobservables and to solve the reflection problem. We investigate peer effects in student achievement in...

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...

I investigate complementarity games played on graphs, which model negative externalities embedded in structures of interaction. On the complete graph, the traditional economic analysis applies: the number of agents playing one strategy is proportional to its payoff. I show that, in general and...

Many environmental policies including the Kyoto Protocol, the Acid Rain Program, the Montreal Protocol and the phase-out of leaded gas are designed to achieve a target level of abatement within a specified period of time. This paper examines how pollution abatement should be allocated over time...

We provide the first empirical application of a new approach proposed by Lee (2007) to estimate peer effects in a linear-in-means model. This approach allows to control for group-level unobservables and to solve the reflection problem. We investigate peer effects in student achievement in...

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...

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...