This paper develops and tests a simple model to explain the origins of municipal segregation ordinances. Passed by cities between 1909 and 1917, these ordinances prohibited members of the majority racial group on a given city block from selling or renting property to members of another racial...

We study the role of homophily in group formation. Using a unique dataset of MBA students, we observe homophily in ethnicity and gender increases the probability of forming teams by 25%. Homophily in education and past working experience increases the probability of forming teams by 17% and 11 %...

Collective action to remedy the losses of open access to common-pool resources often is late and incomplete, extending rent dissipation. Examples include persistent over-exploitation of oil fields and ocean fisheries, despite general agreement that production constraints are needed. Transaction...

We conducted a laboratory experiment to test the comparative statics predictions of a new approach to collective action games based on the method of stability sets. We find robust support for the main theoretical predictions. As we increase the payoff of a successful collective action (accruing...

This paper investigates theoretically and empirically the factional arrangements and dynamics within the Chinese Communist Party (CCP), the governing political party of the People's Republic of China. Our empirical analysis ranges from the end of the Deng Xiaoping era to the current Xi Jinping...

This paper studies both theoretically and empirically the determinants of group formation and of 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...

We develop and analyze a tractable empirical model for strategic network formation that can be estimated with data from a single network at a single point in time. We model the network formation as a sequential process where in each period a single randomly selected pair of agents has the...

This paper examines positive externalities and complementarities in the use of antiviral pharmaceuticals to mitigate pandemic influenza. The paper demonstrates the presence of treatment externalities in simple epidemiological SIR models, and then through simulations of a Global Epidemiological...

Scholars have pointed to ethnic and other social divisions as a leading cause of economic underdevelopment, due in part to their adverse effects on public good provision and collective action. We investigate this issue in post-war Sierra Leone, one of the world's poorest countries. To address...

We study a dynamic model of environmental protection in which the level of pollution is a state variable that strategically links policy making periods. Policymakers are forward looking but politically motivated: they have heterogeneous preferences and do not fully internalize the cost of...