An evaluation of fixed and randomized price sequence on the alcohol purchase task.

Abstract

Factors influencing drug consumption can be effectively evaluated in the context of behavioral economic demand. Specifically, hypothetical purchase tasks (HPTs) allow for estimated drug consumption at a range of prices in which drug administration is not ethically or feasibly possible. With the marked increase of HPTs in behavioral research, understanding methodological influences on responding is paramount. One such methodological consideration is the price sequence, which can be presented in a fixed, ascending order or a randomized sequence. This study compared fixed and fully randomized sequence order with college student drinkers using a within-subjects design. Self-reported consumption revealed that despite some small differences between the fixed and random sequences, consumption preferences were highly similar, regardless of presentation order. These results suggest participants are likely not anchoring their responses to the prior price on a fixed-order sequence. We conclude with a discussion on how these findings provide implications for HPTs and future research.

Presentation matters: Effects of cigarette purchase task design on systematic data and purchasing behavior.

“…Contrast comparisons indicate that the Random presentation produced significantly more failures of the Bounce criterion than the List presentation. These results are consistent with our hypothesis that Random would produce the greatest amount of failures of the unsystematic criteria and with previous reports of greater unsystematic data among random presentation of prices in an alcohol purchase task (Salzer et al, 2021). In terms of unsystematic data, these findings suggest that local effects, but not global effects, of price are sensitive to task presentation.…”

“…Consistent with our hypothesis, Random produced a significantly lower R 2 than List and Ascending; List and Ascending were not significantly different. We observed that the ln(α) of Random was significantly lower than both List and Ascending (i.e., more inelastic), consistent with Salzer et al (2021). Also consistent with these results, ln(O max ) was significantly higher in Random than in List, indicating a higher expenditure at price Pmax (Kaplan et al, 2019).…”

“…Ascending order has been previously recommended (Kaplan et al, 2018). This methodological approach is supported by evidence showing that while differences in alcohol purchase indices between an ascending order and randomized sequence are small, unsystematic data are higher in the randomized sequence compared to an ascending order (Salzer et al, 2021); however, in this study, only alcohol purchases were investigated. Another previous investigation that measured demand for cigarette puffs by consumption under different response requirements showed that progressive ratio schedules (i.e., ascending response requirements) and fixed ratio random sequences produced similar demand indices (Giordano et al, 2001).…”

(Non-) impact of task experience on behavioral economic decision-making.

“…Demand was evaluated across 13 prices from $0.00 [free] to $11 USD, presented in an ascending order (full price range: Free, $0.01, $0.05, $0.13, $0.25, $0.50, $1, $2, $3, $4, $5, $6, $11/drink). An ascending price sequence was used given evidence indicating similar patterns of response for ascending and randomized price sequences, but with higher systematic data rates for ascending sequences (Amlung & Mackillop, 2012; Salzer et al, 2020).…”

Behavioral Economic Demand: How Simulated Behavioral Tasks Can Inform Health Policy

“…Roma et al (2016) provide a general set of guidelines for developing a novel price sequence (see also Reed et al, 2014). With respect to consideration over price sequencing, replicated research indicates little difference in quality or reliability of responding when prices are presented in ascending, descending, or randomized sequences (e.g., Salzer et al, 2021). Although the field would surely benefit from more research to arrive at a definite recommendation, current thinking lends to employing a price sequence that most logically fits with the commodity and framing in question.…”