Heterogeneous Peer Effects in Education

We develop a network model looking at the role of different types of peers in education. The empirical salience of the model is tested using a very detailed longitudinal dataset of adolescent friendship networks. We find that there are strong and persistent peer effects in education but peers tend to be influential only when their friendships last more than a year and not a shorter period of time. In the short run, however, both types of ties have an impact on current grades.