Comprehensive E-cigarette Flavor Bans and Tobacco Use among Youth and Adults

The vast majority of youth e-cigarette users consume flavored e-cigarettes, raising concerns from public health advocates that flavors may drive youth initiation into and continued use of e-cigarettes. Flavors drew further notice from the public health community following the sudden outbreak of lung injury among vapers in 2019, prompting several states to enact sweeping bans on flavored e-cigarettes. In this study, we examine the effects of these comprehensive bans on e-cigarette use and potential spillovers into other tobacco use by youth, young adults, and adults. We utilize both standard difference-in-differences (DID) and synthetic DID methods, in conjunction with four national data sets. We find evidence that young adults decrease their use of the banned flavored e-cigarettes as well as their overall e-cigarette use, by about two percentage points, while increasing cigarette use. For youth, there is some suggestive evidence of increasing cigarette use, though these results are contaminated by pre-trend differences between treatment and control units. The bans have no effect on e-cigarette and smoking participation among older adults (ages 25+). Our findings suggest that statewide comprehensive flavor bans may have generated an unintended consequence by encouraging substitution towards traditional smoking in some populations.