I analyze a new set of data on Korean American adoptees who were quasirandomly assigned to adoptive families. I find large effects on adoptees' education, income, and health from assignment to parents with more education and from assignment to smaller families. Parental education and family size...

The high variance of crime rates across time and space is one of the oldest puzzles in the social sciences; this variance appears too high to be explained by changes in the exogenous costs and benefits of crime. The authors present a model where social interactions create enough covariance...

We examine how people form social networks among their peers. We use a unique data set that tells us the volume of email between any two people in the sample. The data are from students and recent graduates of Dartmouth College. First-year students interact with peers in their immediate...

This paper uses a unique data set to measure peer effects among college roommates. Freshman year roommates and dormmates are randomly assigned at Dartmouth College. I find that peers have an impact on grade point average and on decisions to join social groups such as fraternities. Residential...

Who should enforce laws or contracts: judges or regulators? Many Coasians, though not Coase himself, advocate judicial enforcement. We show that the incentives facing judges and regulators crucially shape this choice. We then compare the regulation of financial markets in Poland and the Czech...

Politicians face a trade-off between the policies that maximize their chances of reelection and their most preferred policies (or the policies most preferred by the constituency which they represent). This paper analyzes this trade-off in a dynamic electoral model in which the voters are not...

This paper studies the equilibrium determination of the number of countries in different political regimes, and in different economic environments, with more or less economic integration. The authors focus on the trade-off between the benefits of large jurisdictions and the costs of...

The authors study the relationship between politics and economic growth in a simple model of endogenous growth with distributive conflict among agents endowed with varying capital/labor shares. They establish several results regarding the factor ownership of the median individual and the level...

This paper studies what determines group formation and the degree of participation when the population is heterogeneous, both in terms of income and race or ethnicity. We are especially interested in whether and how much the degree of heterogeneity in communities influences the amount of...

We present a model that links heterogeneity of preferences across ethnic groups in a city to the amount and type of public goods the city supplies. We test the implications of the model with three related data sets: U. S. cities, U. S. metropolitan areas, and U. S. urban counties. Results show...