The Demand for Vice: Inter-Commodity Interactions with Uncertainty

This paper analyses consumption patterns of vice -- marijuana, tobacco and alcohol. To deal with imperfect marijuana data, we exploit the interdependencies in the consumption of the three drugs identified in prior research, and introduce a Monte Carlo simulation procedure to formally account for the inherent uncertainty in marijuana-related data and parameters. To illustrate the application of the framework, we use Australian data to simulate the impact on the consumption of vice of a reduction in the price of marijuana; changes in pre-existing taxes on tobacco and alcohol; legalisation of marijuana, which is then subject to taxation; and a tax tradeoff involving the introduction of a revenue-neutral tax on marijuana that is offset by reduced alcohol taxation. The revenue-maximising tax rate for marijuana of about 50% is estimated to yield additional revenue of about 15% of the pre-existing proceeds from vice taxation. The role of uncertainty surrounding marijuana is highlighted by providing the entire probability distributions of all endogenous variables in a consistent multivariate framework.