Researchers and educators often argue that a student's peers strongly influence his or her educational outcomes. If so, an unequal distribution of advantaged and disadvantaged students across schools in a community will leave many students doubly disadvantaged and amplify existing inequalities....

A number of studies have indicated that peer smoking is a highly influential factor in a young person's decision to smoke. However, these results are suspect because the studies often fail to account for selection and simultaneity bias. This paper develops an econometric model of youth smoking...