Further examination of the temporal stability of alcohol demand

Abstract

Demand, or the amount of a substance consumed as a function of price, is a central dependent measure in behavioral economic research and represents the relative valuation of a substance. Although demand is often utilized as an index of substance use severity and is assumed to be relatively stable, recent experimental and clinical research has identified conditions in which demand can be manipulated, such as through craving and stress inductions, and treatment. Our study examines the 1-month reliability of the alcohol purchase task in a sample of heavy drinking college students. We also analyzed reliability in subgroup of individuals whose consumption decreased, increased, or stayed the same over the 1-month period, and in individuals with moderate/severe Alcohol Use Disorder (AUD) vs. those with no/mild AUD. Reliability was moderate in the full sample, high in the group with stable consumption, and did not differ appreciably between AUD groups. Observed indices and indices derived from an exponentiated equation (Koffarnus et al., 2015) were generally comparable, although Pmax observed had very low reliability. Area under the curve, Omax derived, and essential value showed the greatest reliability in the full sample (rs = .75–.77). These results provide evidence for relative stability over time and across AUD groups, particularly in those whose consumption remains stable.

The Behavioral Economics of Alcohol Demand in French and American University Students

“…The APT results obtained from our U.S. sample are highly consistent with those obtained from university students at the current site and elsewhere in the United States (Acuff and Murphy, ; Berman and Martinetti, ; Gentile et al., ; MacKillop et al., ; Martinetti et al., ; Murphy and MacKillop, ; Yurasek et al., ). The APT reliably produces an inverse relationship between price and consumption, with binge‐level reported consumption at lower alcohol prices, such as $3.00 or less (Berman and Martinetti, ), and the current U.S. data reflect these results.…”

“…Murphy and colleagues () compared the APT with other instruments that have been shown to accurately measure alcohol consumption and found that the APT produced similar results, thus demonstrating good construct validity. High correlations between test and retest scores on the APT and derived demand indices have been well established (Acuff and Murphy, ; Murphy et al., ), and Amlung and colleagues () observed strong relationships between demand metrics assessed with the APT and those produced from actual alcohol purchases.…”

“…Demand intensity is consumption unconstrained by price (i.e., when drinks are free) (Hursh and Roma, ). Several studies using the APT with university‐student participants have revealed that demand is inelastic at lower alcohol prices, but becomes elastic at higher prices (Acuff and Murphy, ; Berman and Martinetti, ; Gentile et al., ; Murphy and MacKillop, ; Murphy et al., ; Skidmore and Murphy, ) and that minor changes in the APT vignettes can modify both elasticity and intensity of demand (Gentile et al., ; Kaplan and Reed, ). The topography of these relations is consistent with those from other hypothetical purchase tasks, such as those for cigarettes (Few et al., ) and cannabis (Aston et al., ).…”

Evaluating Behavioral Economic Models of Heavy Drinking Among College Students

“…The alcohol purchase task (APT; Murphy & MacKillop, 2006) asks participants to report the number of alcoholic drinks they would purchase and consume at a party between 9:00 PM and 1:00 AM across 20 escalating price points. Although many indices can be calculated using the APT, the current study elected to focus on intensity, elasticity, and O max , as these have shown good reliability (Acuff and Murphy, 2017; Murphy et al, 2009) and the most robust associations with substance misuse (Murphy et al, 2009; Teeters and Murphy, 2015). Further, hypothetical purchase choices have been shown to correspond to actual choices made with real monetary amounts (Amlung et al, 2012).…”

Concurrent validity of the alcohol purchase task in relation to alcohol involvement: protocol for a systematic review and meta-analysis

“…5 Importantly, alcohol demand has been found equivalent under real and hypothetical conditions, where participants do not consume substances purchased. 6 Accordingly, the use of a hypothetical APT has gained interest because of evidence of construct validity, 7 temporal stability 8 and higher efficiency 3 compared with more traditional operant choice procedures such as self-administration paradigms. More recently, there has been an interest in understanding the relative sensitivity of each demand indicator to detect substance-related outcomes and variables affecting them.…”