Adolescent Friendship Networks and Trajectories of Binge Drinking

Michael S. Pollard, RAND Corporation
Harold Green, RAND Corporation
David P. Kennedy, University of North Carolina at Chapel Hill
Myong-Hyun Go, Pardee RAND Graduate School

We examine how adolescent friendship networks are linked to binge drinking trajectories into young adulthood using Add Health. We add to the literature by examining whether an individual’s structural position (group member, liaison or isolate) in friendship networks is linked to longitudinal alcohol use, above and beyond number of drinking friends. Trajectories of "binge drinking episodes per month" are first modeled using semi-parametric longitudinal mixture models. Individuals are assigned to trajectory groups based on posterior probabilities of membership. Friendship network structural characteristics are modeled using NEGOPY. Multinomial logit models of trajectory group membership are then estimated, and include information on network position, number of drinking friends, as well as a range of controls. We identify five trajectories of binge drinking. Structural position is associated with use trajectories: bingeing group membership and liaison to bingeing groups predicts higher trajectories. Network effects are strongly associated with bingeing in school, but not after.