use, higher drinking quantity and frequency across time. The exception is that there is convergence (but not cross-over) over time in average drinks per drinking setting between White and Black female drinkers. Second, for cigarette use, there is robust evidence of convergence in past-30 day cigarette use, as well as using >25 days in the past month and in the number of days of use among users, among both men and women. There was no evidence, however, of a crossover of prevalence between Whites and Blacks. Third, marijuana use was the only outcome for which there was some evidence of cross-over, among women only. Among males, there were few differences in marijuana use or frequency at any time frame; among females, however, there was evidence of convergence and for marijuana users, Whites had higher frequency of use at Wave 1, though by Wave 4, Blacks had higher frequency of use. The study benefitted from one the largest samples examined to date, wide geographic variation, and follow-up into adulthood to examine trajectories of substance use by race/ethnicity in the US.
