A recent study has found that the legalization of marijuana is associated with a decrease in adult tobacco use. Researchers from Bentley, San Diego State, and Georgia State universities analyzed data from the Population Assessment of Tobacco and Health and the National Survey on Drug Use and Health to examine the impact of state-level cannabis reforms on tobacco use. While the adoption of state recreational marijuana laws (RMLs) led to a small increase in cannabis use among adults, tobacco use did not follow that trend. In fact, the study found that if the apparent substitution effect from cigarettes to marijuana were extended nationally, it could result in healthcare cost savings worth more than $10 billion per year.
One concern among public health experts has been that the legalization of marijuana could fuel an increase in the use of tobacco products. However, researchers found “little empirical support” for this hypothesis. Instead, they identified “small, occasionally significant longer-run declines in adult tobacco use.” The study acknowledges that legalization had a “largely statistically insignificant” effect on tobacco use in general but found that in states where recreational marijuana was legalized three or more years ago, there was a 1.4% to 2.7% decline in adult tobacco use. In addition, cigarette use decreased by 1.1% to 1.3% among adults after three or more years following RML enactment.
The study also found that legalization is associated with a lagged reduction in electronic nicotine delivery systems (ENDS) use and that potential healthcare cost savings resulting from substitution away from cigarettes and towards cannabis “could be substantial.” The researchers estimate that a reduction in smoking prevalence by as many as 5.1 million individuals could result in healthcare cost savings of about $10.2 billion per year.
The authors note that their analysis of National Survey on Drug Use and Health data shows “consistent evidence” that the adoption of state recreational marijuana laws led to a slight uptick in cannabis use among adults. However, the reduction in tobacco use in legal states is “primarily concentrated among men and for RMLs that are accompanied by open recreational dispensaries,” suggesting that recreational marijuana is a substitute for some adults.
This study is the first to comprehensively examine the impact of recreational marijuana legalization on tobacco use. The authors acknowledge that their analysis of data from states with legal cannabis that first passed medical marijuana laws means that “RML effects could be conflated with the long-run effects of MMLs.” Nevertheless, the results suggest that state-level cannabis reforms could have important implications for public health and healthcare spending.