Hypothetical Purchase Task Metrics Predict Responding on an Incentivized Purchase Task for Full and Reduced Nicotine Cigarettes.

Introduction: The purchase task procedure offers a rapid data collection method for evaluating drug value in contexts for which drug self-administration is practically or ethically limited. This study addresses a methodological concern with purchase task use - the correspondence between hypothetical and real commodity valuation - by testing task say-do and hypothetical-incentivized correspondence for tobacco demand across varied tobacco products.

Methods: Participants (n = 24; 50% female) completed study sessions characterized by changing cigarette product characteristics. During each session, participants sampled a cigarette varying in blinded nicotine content and nicotine expectancy and completed hypothetical and incentivized purchase tasks for that product. The incentivized task prompted participants to report the number of session cigarettes they would purchase for a within-session self-administration period while the hypothetical task evaluated simulated purchases of cigarette packs for a typical smoking week. Measures of correspondence were evaluated across purchase task metrics.

Results: Across conditions, purchasing and self-administration in the incentivized purchase task and self-administration period showed a strong positive correlation (r = .70, p<.001). Average correlations for each metric between task types ranged from r = .43 [Omax] to r = .55 [breakpoint]. Linear mixed-effects modeling revealed statistically significant predictive relations between hypothetical and incentivized task metrics for Q0 (p<.001), ⍺ (p<.001), intensity (p<.001), Omax (p=.04), Pmax (p=.01), and breakpoint (p<.001).

Conclusions: Data uphold the correspondence between hypothetical and incentivized task responding in the context of familiar and novel cigarette products. Broadly, data provide continued support for the purchase task method as a reliable and ecologically valid method of assessing reinforcer valuation.

Implications: A limited body of research precludes conclusions regarding the say-do correspondence of simulated purchase tasks. This study examines correspondence across a hypothetical task prompting participants to report tobacco valuation in units of packs and an incentivized task prompting participants to report single cigarette consumption for use during a within-session self-administration period. The task correspondence observed in this study supports the continued use of behavioral economic simulated purchase tasks for application in difficult-to-study contexts.