Adaption of commodity purchase tasks to identify substitutable substance-free alternative activities for alcohol use

Behavioral economic frameworks emphasize the importance of contextual influences on alcohol use; therefore, identifying relative demand for alcohol versus other commodities is of importance. Cross-commodity purchase tasks allow participants to make choices across multiple concurrently available commodities and can thereby pinpoint interactions among those commodities. These tasks may help identify relevant substance-free alternative activities to target in alcohol treatment by determining whether the activity functions as a substitute for alcohol use. While substance-free activity promotion is a promising behavioral component of alcohol interventions, no research to-date has used behavioral economic methods to assess the substitutability of alternative activities for alcohol use. The present studies were preliminary assessments of novel single- and cross-commodity purchase tasks of various alternative activities (e.g., exercise, hobbies, civic involvement). Participants in Study 1 recruited from Amazon’s Mechanical Turk (n = 110) were administered a series of novel activity purchase tasks and an alcohol purchase task. Results showed excellent fit of the exponential demand equation to activity purchase task data and provided initial support for adaptation of purchase task methodology to alternative activity demand. In Study 2, participants recruited from Amazon’s Mechanical Turk (n = 108) were administered both single-commodity and cross-commodity purchase tasks of alcohol and exercise. While most participants demonstrate independent consumption of alcohol and exercise, a subset of participants substituted exercise for alcohol as indicated by quantitative cross-price elasticity indices. These response patterns highlight the importance of individual differences and hold implications for recovery efforts that promote alternative activity engagement and public policy.