Eating Behavior and Social Interactions from Adolescence to Adulthood

This paper analyzes the importance of social ties for eating behavior of US youth. We propose a novel approach that addresses identification of social endogenous effects. We overcome the problem of measuring the separate impact of endogenous and contextual effects on individual Body Mass Index (BMI) in a dynamic linear-in-means model, where individual- and group-specifi c unobservable effects are controlled for. We show that the main drivers of eating behavior are habituation and imitation effects. Imitation effects explain most of the variation in BMI of individuals who were normal-weight and overweight during adolescence. Obese adolescents, instead, become future obese adults through wrong habits enforced by imitative behavior