Identification of peer effects through social networks using variance restrictions
提出利用结果变量方差和协方差的波动来识别社交网络中的同伴效应，通过对比同伴与同伴的同伴的结果协方差来区分内生和情境效应，并应用于STAR项目数据发现幼儿园学生学业成绩中存在显著正向同伴效应。
This paper presents a novel method to identify peer effects through exploiting fluctuations in the variances and covariances of outcomes over a social network. Endogenous and contextual peer effects can be disentangled by contrasting the covariances of the outcomes of peers with the covariances of the outcomes of peers of peers. Correlated effects are incorporated by allowing for unrestricted network level heterogeneity. The method is applied to the Project STAR data to study peer effects in academic attainment of first‐year kindergarten students. Evidence is found of positive peer effects, which are statistically significant and consistent with the existing literature.