Concerns over the excessive use of mobile phones, especially among youths and young adults, are growing. We present, to our knowledge, the first estimates of both behavioral spillover and contextual peer effects, as well as the first comprehensive evidence of how own and peers' mobile app usage...

An extensive literature in the social sciences analyzes peer effects among students, but estimation is complicated by several major problems some of which cannot be solved even with random assignment. We design a field experiment and propose a new estimation technique to address these estimation...

We examine how peers influence the allegiances of West Point cadets in the American Civil War. Specifically, we analyze how quasi-random variations in the proportion of cadets from northern (low-slave) states influenced the decisions of cadets in choosing which army to join. A higher proportion...

An extensive literature in the social sciences analyzes peer effects among students, but estimation is complicated by several major problems some of which cannot be solved even with random assignment. We design a field experiment and propose a new estimation technique to address these estimation...