We propose to quantify population-level trends in tobacco use in order to inform both California’s tobacco control policies and the FDA’s regulatory actions over tobacco products. The proposed studies will analyze the large federally-sponsored surveys of tobacco use, including the new FDA-sponsored PATH longitudinal survey. We aim to target specific questions of direct relevance to both state level tobacco control policy and to potential FDA regulatory action. Our broad area of investigation is association of marketing and use of non-cigarette tobacco products with smoking initiation among youth and young adults, and with smoking cessation behavior among established smokers. The analyses will control for known predictors of tobacco use behaviors which are susceptible to state-level tobacco control efforts, such as local smoking prevalence or presence of a smoke-free home. Specific areas of potential interest to policy makers and regulators include measuring the susceptibility to tobacco industry marketing efforts among youth and young adults; investigating how concurrent use of cigarettes and other tobacco products affects cigarette smoking behavior; and documenting changing patterns of cigarette smoking cessation in response to the new tobacco products on the market, at the population level. We propose to document and quantify these associations within the US population as a whole, and to identify trends and associations that have disproportionate impact among vulnerable subgroups. The targeted demographic groups for which we expect to have adequate sample sizes include racial/ethnic minorities, those with poor mental health, and less educated and less affluent populations.