title: Controlling for the endogeneity of peer substance use on adolescent alcohol and tobacco use.
abstract: This study examines whether the effects of peer substance use on adolescent alcohol and tobacco use are due to endogeneity of adolescents selecting their peer group. We analyzed data collected for a longitudinal analysis of a drug-use prevention programme for upper elementary school students. We used a two-step probit regression to control for the potentially endogenous explanatory variable peer substance use. Rigorous tests of endogeneity and the validity of the instrumental variables showed that controlling for the endogeneity of peer substance use to reduce bias is not worth the reduction in mean squared error in these data. Peer substance use has a positive and significant effect on adolescent substance use for both drinking and smoking. These results imply that peer influence is empirically more important than peer selection (endogeneity) in our sample of adolescents in grades 6-9. Living in a single-parent family was by far the strongest predictor of adolescent drinking and smoking.
authors.affiliation: University of North Carolina at Chapel Hill, 27599-7400, USA. edward_norton@unc.edu
authors.forename: E C
authors.initials: EC
authors.lastname: Norton
authors.forename: R C
authors.initials: RC
authors.lastname: Lindrooth
authors.forename: S T
authors.initials: ST
authors.lastname: Ennett
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000428:Alcohol Drinking / Q000453:epidemiology*; D002648:Child; D016208:Databases, Factual / Q000592:standards / Q000706:statistics & numerical data; D005192:Family Health; D005260:Female; D015438:Health Behavior; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010379:Peer Group; D012044:Regression Analysis; D012107:Research Design / Q000592:standards; D012111:Residence Characteristics; D012307:Risk Factors; D015983:Selection Bias; D012907:Smoking / Q000453:epidemiology*; D012931:Social Environment; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology