The effect of social networks on students’ academic and non-cognitive behavioural outcomes: Evidence from conditional random assignment of friends in school

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’ socio-economic background. These gains might be partly mediated through greater cooperation, reduction in violent behaviour and improvements in social satisfaction in class.