Cultural psychologists and anthropologists argue that societies have developed heterogeneous systems of social organization to cope with social dilemmas, and that an entire bundle of psychological and biological characteristics has coevolved to enforce cooperation within these different regimes....

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 find that sin good purchases are highly concentrated with 10% of households paying more than 80% of taxes on alcohol and cigarettes. Total sin tax burdens are poorly explained by demographics (including income), but are well explained by eight household clusters defined by purchasing...

We investigate a method for eliciting relative poverty rankings that aggregates partial poverty rankings obtained from multiple individuals. We first demonstrate that the method works in principle, then apply it in urban Côte d'Ivoire. We find that constructed rankings are often incomplete, not...

We study when and why firms exercise real options. Using detailed project-level investment data, we find that the likelihood that a firm exercises a real option is strongly related to peer exercise behavior. Peer exercise decisions are as important in explaining exercise behavior as variables...

This paper examines how elementary-aged peers affect cognitive and non-cognitive outcomes from adolescence to adulthood. We identify effects by exploiting within-school and within-neighborhood variation in the proportion of peers with an arrested parent. Results indicate exposure to these peers...

We study the nature of peer effects in the market for new cell phones. Our analysis builds on de-identified data from Facebook that combine information on social networks with information on users' cell phone models. To identify peer effects, we use variation in friends' new phone acquisitions...

Pharmaceutical companies' marketing efforts primarily target physicians, often through individual detailing that entails monetary or in-kind transfers. We study how peer influence broadens these payments' reach beyond the directly paid physicians. Combining Medicare prescriptions and Open...

We analyze how separations responded to arbitrary differences in own and peer wages at a large U.S. retailer. Regression-discontinuity estimates imply large causal effects of own wages on separations, and on quits in particular. However, this own-wage response could reflect comparisons either to...

We study the effects of peer gender composition, a proxy for female-friendliness of environment, in STEM doctoral programs on persistence and degree completion. Leveraging unique new data and quasi-random variation in gender composition across cohorts within programs, we show that women entering...