We study social interactions in the risky behavior of best-friend pairs in the National Longitudinal Study of Adolescent Health (Add Health). Focusing on friends who had not yet initiated a particular behavior (sex, smoking, marijuana use, truancy) by the first wave of the survey, we estimate...

This paper estimates treatment size and status specific peer effects that are not detected by widely-used approaches to the estimation of spillovers. In a field experiment using university students, we find that subjects who have been incentivized to exercise increase gym usage more if they have...

Does the lack of peers contribute to the observed gender gap in entrepreneurial success, and is the constraint stronger for women facing more restrictive social norms? We offered two days of business counseling to a random sample of customers of India's largest women's bank. A random subsample...

We study risky behavior of adolescents. Concentrating on smoking and alcohol use, we structurally estimate a dynamic social interaction model in the context of students' school networks included in the National Longitudinal Study of Adolescent Health (Add Health). The model allows for...

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...

Using longitudinal elementary school teacher and student data, we document that students have larger test score gains when their teachers experience improvements in the observable characteristics of their colleagues. Using within-school and within-teacher variation, we further show that a...

This paper uses a variety of individual-level survey data from several countries to test for interactions between subjective well-being at different ages and variables measuring the nature and quality of the social context at work, at home, and in the community. While earlier studies have found...

Are individuals more likely to smoke when they are surrounded by smokers? In this paper, we examine the evidence for peer effects in smoking. We address the endogeneity of peers by looking at the impact of workplace smoking bans on spousal and peer group smoking. Using these bans as an...

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...

Little is known about the economic mechanisms leading to the high level of clustering in behavior commonly observed in the data. We present a model where agents can interact according to three distinct mechanisms, and we derive testable implications which allow us to distinguish between the...