Abstract
BACKGROUND AND AIMS: Although over half of United States states have passed taxes on electronic nicotine delivery systems (ENDS), recent evidence links ENDS tax rates to increases in smoking, suggesting potentially substantive health costs. Overall health implications will depend on how these taxes affect transitions from experimentation to regular smoking and vaping. Current analyses have not assessed ENDS tax rates' effects in young adulthood (ages 18-25). This study measures the relationship between ENDS and cigarette tax rates and ENDS use and smoking in young adulthood, a key period for initiation of regular tobacco use. DESIGN: Observational study of data from the Current Population Survey's 2010-2019 Tobacco Use Supplements. SETTING: The United States. PARTICIPANTS/CASES: A total of 38 906 18 to 25 year-olds MEASUREMENTS: Multivariable linear regressions estimated two-way fixed effects analyses to assess ENDS and cigarette tax rates' relationships to recent and daily smoking and vaping, adjusting for an array of potential sociodemographic and policy confounders along with state and year fixed effects. FINDINGS: A $1 increase in ENDS taxes yielded significant reductions in young adults' daily vaping ( β̂ = -0.025; 95% CI, -0.037, -0.014) alongside increases in recent smoking ( β̂ = 0.037; 95% CI, 0.013, 0.061), primarily reflecting greater dual use ( β̂ =2.078; 95% CI, 0.890, 4.852; P = 0.09). A $1 cigarette tax increase yielded 2.1 and 2.5 percentage point increases in recent and daily vaping, with 95% CIs of (0.004, 0.038) and (0.018, 0.032) respectively. CONCLUSIONS: In the United States, higher ENDS tax rates are associated with decreased ENDS use but increased cigarette smoking among 18- to 25-year-olds, with associations reversed for cigarette taxes.