Social network effects in alcohol consumption among adolescents.

In this paper we seek to empirically quantify the role of peer social networks in explaining drinking behavior among adolescents. Using data from a nationally representative sample of adolescents we utilize a multivariate structural model with school-level fixed effects to account for the problems of contextual effects, correlated effects and peer selection to purge the potential biases from the estimates of peer influence. Our peer group measures are drawn not only from the nomination of close friends, but also from classmates. Drinking behavior among the peer groups was constructed using the peers' own report of their alcohol consumption. Controlling for parent level characteristics, and other demographic parameters, we find that a 10% increase in the proportion of classmates who drink will increase the likelihood of drinking participation and frequency by approximately four percentage points. We also find evidence to show that the influence of close friends, while still significant, diminishes in magnitude after accounting for unobserved environmental confounders. Our findings support the literature that peer effects are important determinants of drinking behavior even after controlling for potential biases. Effective policy aimed at reducing alcohol consumption among adolescents would consider these significant peer effects. 2009 Elsevier Ltd. All rights reserved.