Behavioral Economic Relationship between Marijuana and Cigarettes: Evidence from Simulated Purchase Tasks

Background: Concurrent use of marijuana and cigarettes is common particularly among marijuana users. It is associated with elevated risks compared to using one substance alone. While cigarette prices are continuously increasing, marijuana price in states with marijuana commercialization has dropped significantly due to economies of scale and elimination of production barriers. The diverging regulatory strategies of marijuana and tobacco control may generate unintended consequences through policy interactions. Meanwhile, existing evidence about the relationship between marijuana and cigarettes is mixed and inconclusive. In this study, we aim to examine the economic relationship between marijuana and cigarettes and project the impacts of price/tax increases on both substances.

Methods: We will recruit 1,000 adult marijuana users from states that have opened or planned to open retail sale of recreational marijuana, including California, Colorado, Washington, Oregon, Nevada, Massachusetts, Maine, and Michigan. These marijuana users should have used marijuana at least once in the past 12 months and be 21 years or older. The demographics of the sample will be quota matched to represent the national marijuana user population. Using web-based survey, participants will complete single commodity simulated purchase tasks, indicating the quantity of marijuana dried flowers or cigarette packs at 11 escalating prices when only one commodity is available. They will then complete cross-commodity simulated purchase tasks indicating the quantities of marijuana dried flowers or cigarette packs, assuming the price of cigarette packs remains constant and both commodities are concurrently available. The recruitment of participants and online survey will be implemented and completed in May 2019.

Expected Results: We will estimate single-commodity demand indices for marijuana dried flowers and cigarette packs; the indices will include intensity of demand, peak expenditure, price at peak expenditure, breakpoint price, and own elasticity. We will also estimate cross-price elasticity and demand curves for the two commodities.

Policy Implications: Our results are expected to provide additional evidence on marijuana and cigarette relationship as well as important implications regarding marijuana and tobacco policy interactions.