Toward a General Theory of Peer Effects
提出一个放松线性假设的同伴效应一般模型，涵盖溢出、从众和线性均值模型作为特例，并用美国青少年数据估计模型，发现线性均值模型在许多活动中不成立，基于均值的社会规范会导致错误政策。
There is substantial empirical evidence showing that peer effects matter in many activities. The workhorse model in empirical work on peer effects is the linear‐in‐means (LIM) model, whereby it is assumed that agents are linearly affected by the mean action of their peers. We develop a new general model of peer effects that relaxes the linear assumption of the best‐reply functions and the mean peer behavior and that encompasses the spillover, conformist model, and LIM model as special cases. Then, using data on adolescent activities in the United States, we structurally estimate this model. We find that for many activities, individuals do not behave according to the LIM model. We run some counterfactual policies and show that imposing the mean action as an individual social norm is misleading and leads to incorrect policy implications.