the estimation of spillovers. In a field experiment using university students, we find that subjects who have been …

assigned to peer groups of about 30 students with whom they are required to spend the majority of their time interacting. This …

observed patterns of interaction. We find that, while much sorting exists at all stages of college, black and white students … friends as randomly assigned roommates of the same race. Further, we find that, in the long-run, white students who are … randomly assigned black roommates have a significantly larger proportion of black friends than white students who are randomly …

Using longitudinal elementary school teacher and student data, we document that students have larger test score gains … within-teacher variation, we further show that a teacher's students have larger achievement gains in math and reading when …