Do State Tobacco 21 Laws Work?

Abstract

Tobacco 21 (T-21) laws prohibit the sale of tobacco products to individuals under age 21. This study is the first to comprehensively examine the impacts of statewide T-21 laws on youth tobacco consumption, including spillovers to minor teens. Using data from the 2009-2019 Behavioral Risk Factor Surveillance Survey (BRFSS) and a difference-in-differences approach, we find that the enactment of a statewide T-21 law was associated with a 2.5 to 3.9 percentage-point decline in smoking participation among 18-to-20-year-olds. A causal interpretation of our estimates is supported by event-study analyses and falsification tests for young adults ages 21 and older. Next, using data from the 2009-2019 State Youth Risky Behavior Surveys (YRBS), we find that statewide T-21 laws reduced tobacco cigarette and electronic cigarette (e-cigarette) consumption among 18-year-old high school students. However, descriptive evidence suggests that the negative impact of T-21 laws on e-cigarette use among 18-year-olds may be partially blunted by an increase in borrowing e-cigarettes from others. Finally, we find that T-21 laws generate important spillovers including (i) a reduction in tobacco cigarette use among 16-to-17-year-olds, a group that relies heavily on the “social market” — including 18-year-old peers — to access tobacco, and (ii) reductions in both marijuana use and frequency of alcohol consumption among older teenagers.

Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.