PEER EFFECTS IN ADOLESCENT BMI: EVIDENCE FROM SPAIN
基于西班牙中学生调查数据，研究发现朋友平均BMI对青少年BMI有显著正向因果影响，且效应强于美国研究，并揭示了同伴压力对特定青少年亚群的影响。
This paper extends the recent literature on the influence of peers on adolescent weight on three new fronts. First, based on a survey of secondary school students in Spain in which peers are formed by nominated classmate friends, we find a more powerful positive and significant causal effect of friends' mean BMI on adolescent BMI than previous US-based research. These results are in line with international data, which show that peer group contact tends to vary across countries. Our findings cover a large set of controls, fixed effects, the testing of correlated unobservables, contextual influences and instrumental variables. Second, social interactions are identified through the property of intransitivity in network relationships. Finally, we report evidence of a strong, positive effect of peer pressure on several subgroups of adolescents in an attempt to study their vulnerability to social influences.