Behavioral Effects of the California Flavored Tobacco Ban on Adult Cigarette Smoking: A Difference-in-Differences Analysis Using U.S. National Data

In December 2022, California enacted a comprehensive ban on the sale of flavored tobacco products, including menthol cigarettes. Using data from the Behavioral Risk Factor Surveillance System, this study employed difference-in-differences (DiD) models to examine adult smoking prevalence in California before (January 2017-December 2022) and after the ban (January 2023-December 2024), compared to states without flavor bans. From 2017-2024, smoking prevalence declined steadily in both California (from 11.8% to 7.9%) and the comparator states (from 18.5% to 12.4%). Adjusting for sociodemographic and year-fixed effects, the DiD estimate among adults 21+ was not significant (aOR=1.09; 95% CI: 1.00-1.20; p=0.0522). However, DiD effects showed significantly lower cigarette decline for age 21-34 (aOR=1.26; 95% CI: 1.05-1.52; p=0.0146) and for Hispanic adults (aOR=1.19; 95% CI: 1.01-1.41; p=0.0433). These results suggest that the flavor ban in California did not significantly affect overall adult 21+ smoking prevalence compared to states without such policies but may have reduced the decline in cigarette smoking among adults aged 21-34 and Hispanic individuals.