Knowledge that Transforms

I examine the effects of the ethnic enclave size on labor market outcomes of immigrants. I account for ability sorting into enclaves by exploiting a Danish spatial dispersal policy under which refugees were randomly dispersed across locations. First, I find strong evidence that refugees with unfavorable unobserved characteristics self‐select into ethnic enclaves. Second, a relative standard deviation increase in the ethnic enclave size increases annual earnings by 18% on average, irrespective of skill level. Third, further findings are consistent with the explanation that ethnic networks disseminate job information, which increases the job‐worker match quality and thereby the hourly wage rate.

We estimate peer effects in college achievement using a data set in which individuals are exogenously assigned to peer groups of about 30 students with whom they are required to spend the majority of their time interacting. This feature enables us to estimate peer effects that are more comparable to changing the entire cohort of peers. Using this broad peer group, we measure academic peer effects of much larger magnitude than found in previous studies. The effects persist at a diminished rate into follow-on years, and we find evidence of nonlinearities in the magnitude of the effects across student academic ability. (c) 2009 by The University of Chicago.