This paper uses a unique data set to measure peer effects among college age roommates. Freshman year roommates and dormmates are randomly assigned at Dartmouth College. I find that in this group, peer effects are very important in determining levels of academic effort and in decisions to join...

A common practice in the fields of education, mental health, and juvenile justice is to segregate problem youths in groups with deviant peers. Assignments of this sort, which concentrate deviant youths, may facilitate deviant peer influence and lead to perverse outcomes. This possibility adds to...

This paper develops a theory of promotion based on evaluations by the already promoted. The already promoted show some favoritism toward candidates for promotion with similar beliefs, just as beetles are more prone to eat the eggs of other species. With such egg-eating bias, false beliefs may...

Should the national government undertake policies aimed at strengthening the economies of particular localities or regions? Agglomeration economies and human capital spillovers suggest that such policies could enhance welfare. However, the mere existence of agglomeration externalities does not...

"Changes in technologies for reproducing and redistributing digital goods (e.g., music, movies, software, books) have dramatically affected profitability of these goods, and raised concerns for future development of socially valuable digital products. However, broader illegitimate distribution...

"We identify a new set of stylized facts on the 2008-2009 trade collapse that we hope can be used to shed light on the importance of demand and supply-side factors in explaining the fall in trade. In particular, we decompose the fall in international trade into product entry and exit, price...

Since 1977, and in some cases starting before that, most East Asian countries' export patterns in manufacturing have been transformed from industry distributions typical of developing countries to distributions more like those of advanced countries. The process of change in most cases started...