Empirical evidence on peer intermediation lags behind many years of lending practice and a large body of theory in which lenders use peers to mitigate adverse selection and moral hazard. Using a simple referral incentive mechanism under individual liability, we develop and implement a two-stage...

Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate largely because of disagreement about (1) whether value-added (VA) provides unbiased estimates of teachers' impacts on student achievement and (2) whether high-VA...

We conducted a field experiment in a 401(k) plan to measure the effect of disseminating information about peer behavior on savings. Low-saving employees received simplified plan enrollment or contribution increase forms. A randomized subset of forms stated the fraction of age-matched coworkers...

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 compares two methods to encourage socially optimal provision of a public good. We compare the efficacy of vigilante justice, as represented by peer-to-peer punishment, to delegated policing, as represented by the "hired gun" mechanism, to deter free riding and improve group welfare....

To what extent do peers affect our occupational choices? This question has been of particular interest in the context of entrepreneurship and policies to create a favorable environment for entry. Such influences, however, are hard to identify empirically. We exploit the assignment of students...

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...

We take cohorts of entering freshmen at the United States Air Force Academy and assign half to peer groups with the goal of maximizing the academic performance of the lowest ability students. Our assignment algorithm uses peer effects estimates from the observational data. We find a negative and...

We study the distributional consequences of the Covid-19 pandemic's impacts on employment, both during the onset of the pandemic and over recent months. Using cross-sectional and matched longitudinal data from the Current Population Survey, we show that the pandemic has exacerbated pre-existing...

The focus of this paper is the endogenous formation of peer groups. In our model, agents choose peers before making contributions to public projects, and they differ in how much they value one project relative to another. Thus, the groups preference composition affects the type of contributions...