教育中的同伴效应是指宿舍、班级、年级或学校内同伴的背景、行为及产出对学生产出或行为的影响。教育中的同伴效应起初使用的是同质性模型，即认为无论个体如何选择同伴，总效益是不变的，同伴效应是一种零和现象。进而发展到异质性模型，即认为同伴效应对不同个体的作用结果是不一样的，通过合理的分配能够提高总效益。研究方法则从以普通最小二乘法为主的统计关联研究，发展到借助于随机实验、自然实验以及准实验的因果推断研究。同伴效应的研究为正确地认识和评价相关教育政策，获得最优组织学校教学的方式，提高教学效率提供了依据。

The concept of peer effect in education is that the behavior or outcome of one student is affected by the characteristic, behavior or outcome of peers in dormitory, class, grade, or school. The initial research model is the homogeneous model that treats peer effect as zerosum phenomena, namely no matter how individuals choose peers, total benefit is the same. However,the heterogeneity mode implies that the total benefit can improve by the reasonable distribution of peers, because the peer effect for different students is different. The research method also changed, the statistical correlation, such as OLS, is replaced by the causal inference, such as random experiment, natural experiment and quasiexperiment. The research of peer effect is not only beneficial to correctly recognize and evaluate relevant education policy, but also beneficial to correctly guide and optimally organize the school teaching.