Does Your Cohort Matter? Measuring Peer Effects in College Achievement
利用学生被外部分组到约30人固定小组的数据，估计了比以往研究更大的同伴效应，并发现效应在后续年份减弱且存在非线性特征。
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.