U.S.: With marijuana legalization, monthly sales of high calorie food increased by 3.2 percent when measured by sales and 4.5 percent when measured by volume

Recreational Marijuana Laws and Junk Food Consumption. Michele Baggio, Alberto Chong. Economics & Human Biology, September 1 2020, 100922. https://doi.org/10.1016/j.ehb.2020.100922

Highlights
• Our research is the first that causally links cannabis consumption to junk food consumption.
• We apply a difference-in-difference approach by exploiting differences in the timing of the legalization of recreational marijuana (RML) across the United States and compare junk food retail sales at the county level.
• In counties located in RML states monthly sales of high calorie food increased by 3.2 percent when measured by sales and 4.5 percent when measured by volume when using our preferred identification strategy.
• Results are robust to including placebo effective dates for RMLs in treated states as well as when using Synthetic Control Methods as an alternative methodology.

Abstract: We use retail scanner data on purchases of high calorie food to study the causal relationship between recreational marijuana laws (RMLs) and consumption of high calorie food. To do this we exploit differences in the timing of introduction of recreational marijuana laws among states and find that they are complements. Specifically, in counties located in RML states monthly sales of high calorie food increased by 3.2 percent when measured by sales and 4.5 percent when measured by volume when using our preferred identification strategy. Results are robust to including placebo effective dates for RMLs in treated states and products as well as when using Synthetic Control Methods as an alternative methodology.

Keywords: Junk FoodDiff-in-DiffRecreational Marijuana LawsSynthetic Controls