Assessing Cannabis Demand: A Comprehensive Review of the Marijuana Purchase Task.

The marijuana purchase task (MPT) is a behavioral economic measure of individualized cannabis value (i.e., demand). The MPT follows purchase tasks for other substances (e.g., alcohol, tobacco), though presents with unique caveats due to its mixed illicit status, non-uniform units of purchase and use, and substantial within substance variability in strain, potency, and quality. As the regulatory climate surrounding purchase and use of cannabis continues to evolve in the USA and globally, rigorous assessment of cannabis use and value are of the utmost importance. This study represents the first comprehensive review of investigations utilizing the MPT. Searches through PubMed and Web of Science databases by two independent coders identified 15 empirical articles referencing the use of an MPT and were published through the year 2019. Articles were coded for demographic and procedural characteristics, structural characteristics of the MPT itself, data analytic characteristics, and relationships with cannabis-related outcomes. Rigorous assessment of demand for cannabis is essential with respect to the broad public health issues surrounding cannabis legalization. We have synthesized the research presented herein and comment on vital considerations for subsequent MPT work, including recommendations for a unified approach to using the MPT in subsequent research.