The Effect of Social Networks on Students' Academic and Non-cognitive Behavioural Outcomes: Evidence from Conditional Random Assignment of Friends in School
利用以色列学生从小学升入初中时朋友关系的随机分配，研究发现朋友数量对学生学业的影响因朋友类型和社会经济背景而异，部分通过合作、减少暴力和提高社交满意度实现。
We investigate the impacts of separating students in Israel from pre-existing social relationships during the transition from elementary to middle school on their academic progress. We define several types of friendships using students’ self-defined friendship nomination and rely for identification on the random assignment of students to classes within a given school. Our results suggest that the number of friends has positive or negative effects on students’ educational outcomes, depending on the type of and on friends’ socioeconomic background. These gains might be partly mediated through greater cooperation, reduction in violent behaviour and improvements in social satisfaction in class.