3. Method
3.1. Data
Hypotheses are tested using waves I, II and III of the National Longitudinal Study of Adolescent Health (Add Health), in-home interviews and parent interviews (Harris,2008). Add Health is a nationally representative study of the health and well-being of US adolescents in grades 7–12
who were enrolled in school during 1994–1995. Respondents were selected from a school-based stratified random sample of 80 high schools and 52 feeder middle schools across the United States sampled with unequal probability of selection (Harris, 2008). In-home interviews for the core sample of respondents (n = 12,105) occurred during years 1994–1995 for adolescents and a fulltime residential parent or guardian for wave I, 1995–1996 for wave II (retention rate 71% of wave I adolescents), and 2001–2002 for wave III (retention rate 73% of wave I adolescents).