How Do Peers Influence BMI? Evidence from Randomly Assigned Classrooms in South Korea
Obesity among children is an important public health concern, and social networks may play a role in students' habits that increase the likelihood of being overweight. We examine data from South Korean middle schools, where students are randomly assigned to classrooms, and exploit the variation in peer body mass index. We use the number of peers' siblings as an instrument to account for endogeneity concerns and measurement error. Heavier peers increase the likelihood that a student is heavier; there is no spurious correlation for height, which is unlikely to have peer contagion. Public policy that targets obesity can have spillovers through social networks.
We are grateful to Corneliu Bolbocean, Mark Hoekstra, and Jason Lindo for helpful comments. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.
Jaegeum Lim & Jonathan Meer, 2017. "How do peers influence BMI? Evidence from randomly assigned classrooms in South Korea," Social Science & Medicine, . citation courtesy of