We develop a Roy model of social interactions in which individuals sort into peer groups based on comparative advantage. Two key results emerge: First, when comparative advantage is the guiding principle of peer group organization, the effect of moving a student into an environment with...

This paper uses the random assignment of playing partners in professional golf tournaments to test for peer effects in the workplace. We find no evidence that the ability of playing partners affects the performance of professional golfers, contrary to recent evidence on peer effects in the...

This paper develops a model of social interactions with endogenous association. People are assumed to invest in relationships to maximize their utility. Even in a linear-in-means model, when associations are endogenous, the effect of macro-group composition on behavior is non-linear and varies...

This paper studies the interactions between an individual's self esteem and his social environment in the workplace, at school, and in personal relationships. Because a person generally has only imperfect knowledge of his own abilities, people who derive benefits from his performance (parent,...

Economists have long been ambivalent about whether the discipline should focus on the analysis of markets or should be concerned with social interactions more generally. Recently the discipline has sought to broaden its scope while maintaining the rigor of modern economic analysis. Major...

We develop a theory of interstate conflict in which the degree of genealogical relatedness between populations has a positive effect on their conflict propensities because more closely related populations, on average, tend to interact more and develop more disputes over sets of common issues. We...

In SIR models, infection rates are typically exogenous, whereas individuals adjust their behavior in reality. City-level data across the globe suggest that mobility falls in response to fear, proxied by Google searches. Incorporating experimentally validated measures of social preferences at the...

There is a large and diverse body of evidence that people condition their behavior on the characteristics of others. If type is visible then one agent seeing another with whom they are interacting, or observing some other close proxy for type, can affect outcomes. We explore the economics of...

We present an infinite-horizon model of moral standards where self-esteem and unconscious drives play key roles. In the model, an individual receives random temptations (such as bribe offers) and must decide which to resist. Individual actions depend both on conscious intent and a type...

Most economic analyses presume that there are limited differences in the prior beliefs of individuals, as assumption most often justified by the argument that sufficient common experiences and observations will eliminate disagreements. We investigate this claim using a simple model of Bayesian...