Temporal stability of a cigarette purchase task.

INTRODUCTION: Cigarette purchase tasks (CPTs) are relatively new behavioral economic assessments that efficiently quantify motivation for tobacco by assessing how much an individual values cigarettes. This is achieved by assessing estimated cigarette consumption at escalating levels of price per cigarette and generating several measures of motivation from the resulting demand curve. The temporal stability of the indices generated from a CPT has not been examined to date and was the focus of the current study.
METHODS: Participants were 11 moderately heavy smokers from the community who completed CPTs and other measures on 2 occasions 1 week apart. The CPT indices of the relative value of cigarettes were (a) intensity (i.e., consumption under minimal cost), (b) O(max) (i.e., maximum expenditure for cigarettes), (c) breakpoint (i.e., first price suppressing consumption to 0), and (d) elasticity (i.e., proportionate price sensitivity).
RESULTS: Demand for cigarettes was initially insensitive to price changes (inelastic) but became increasingly sensitive (elastic) as prices increased. Correlations between the demand indices at both administrations were very high magnitude and statistically significant (rs = .76-.99, ps < .001), and no significant within-subjects differences were present.
CONCLUSIONS: These findings provide initial support for the temporal stability of motivation for tobacco as measured by a CPT. Future studies with larger samples and timeframes will be important to verify these findings.