Concurrent validity of the Alcohol Purchase Task for measuring the reinforcing efficacy of alcohol: an updated systematic review and meta-analysis

Value-based decision-making in regular alcohol consumers following experimental manipulation of alcohol value

BACKGROUND

Devaluation of alcohol leads to reductions in alcohol choice and consumption; however, the cognitive mechanisms that underpin this relationship are not well-understood. In this study we applied a computational model of value-based decision-making (VBDM) to decisions made about alcohol and alcohol-unrelated cues following experimental manipulation of alcohol value.

METHOD

Using a pre-registered within-subject design, thirty-six regular alcohol consumers (≥14 UK units per week) completed a two-alternative forced choice task where they chose between two alcohol images (in one block) or two soft drink images (in a different block) after watching videos that emphasised the positive (alcohol value), and separately, the negative (alcohol devalue) consequences of alcohol. On each block, participants pressed a key to select the image depicting the drink they would rather consume. A drift-diffusion model (DDM) was fitted to reaction time and choice data to estimate evidence accumulation (EA) processes and response thresholds during the different blocks in each experimental condition.

FINDINGS

In the alcohol devalue condition, soft drink EA rates were significantly higher compared to alcohol EA rates (p = 0.04, d = 0.31), and compared to soft drink EA rates in the alcohol value condition (p = 0.01, d = 0.38). However, EA rates for alcoholic drinks and response thresholds (for either drink type) were unaffected by the experimental manipulation.

CONCLUSIONS

In line with behavioural economic models of addiction that emphasise the important role of alternative reinforcement, experimentally manipulating alcohol value is associated with changes in the internal cognitive processes that precede soft drink choice.

Contextual and psychosocial factors influencing drug reward in humans: The importance of non-drug reinforcement

The reinforcing efficacy, or behavior-strengthening effect, of a substance is a critical determinant of substance use typically quantified by measuring behavioral allocation to the substance under schedules of reinforcement with escalating response requirements. Although responses on these tasks are often used to indicate stable reinforcing effects or trait-level abuse potential for an individual, task designs often demonstrate within-person variability across varying degrees of a constraint within experimental procedures. As a result, quantifying behavioral allocation is an effective approach for measuring the impact of contextual and psychosocial factors on substance reward. We review studies using laboratory self-administration, behavioral economic purchase tasks, and ambulatory assessments to quantify the impact of various contextual and psychosocial factors on behavioral allocation toward consumption of a substance. We selected these assessment approaches because they cover the translational spectrum from experimental control to ecological relevance, with consistent support across these approaches representing greater confidence in the effect. Conceptually, we organized factors that influence substance value into two broad categories: factors that influence the cost/benefit ratio of the substance (social context, stress and affect, cue exposure), and factors that influence the cost/benefit ratio of an alternative (alternative non-drug reinforcers, alternative drug reinforcers, and opportunity costs). We conclude with an overview of future research directions and considerations for clinical application.

Correspondence between the alcohol-P3 event-related potential and alcohol reward phenotypes among young adults

BACKGROUND

Behavioral economic theory suggests that the value of alcohol depends upon elements of the choice context, such that increasing constraints on alternatives (e.g., price) or increasing the benefits of alcohol (e.g., social context) may result in greater likelihood of heavy drinking. The P3 event-related potential elicited by alcohol-related cues, a proposed marker of incentive salience, may be an electrophysiological parallel for behavioral economic alcohol demand. However, these indices have not been connected in prior research, and studies typically do not disaggregate social influences in the context of alcohol cue reactivity.

METHOD

The current study recruited heavy drinking young adults (N = 81) who completed measures of alcohol use and alcohol demand, in addition to a 2 (social/nonsocial) × 2 (alcohol/nonalcohol) visual oddball task to elicit the P3.

RESULTS

In multilevel models controlling for demographic characteristics, P3 reactivity was greater to alcohol (p < 0.001) and social (p < 0.001) cues than to nonalcohol and nonsocial cues, but without a significant interaction. Higher alcohol consumption (p = 0.02) and lower elasticity of demand (p = 0.01) were associated with greater P3 response to alcohol than nonalcohol cues.

CONCLUSIONS

The results highlight a brain-behavior connection that may be an important marker for alcohol reward across units of analysis and may be sensitive to changes in the economic choice contexts that influence the likelihood of alcohol use.

Neural correlates of increased alcohol demand following alcohol cue exposure in adult heavy drinkers

Alcohol use disorder is associated with overvaluation of alcohol relative to other rewards, in part due to dynamic increases in value in response to alcohol-related cues. In a neuroeconomic framework, alcohol cues increase behavioral economic demand for alcohol, but the neural correlates these cue effects are unknown. This functional magnetic resonance imaging study combined a neuroeconomic alcohol purchase task with an alcohol cue exposure in 72 heavy drinkers with established sensitivity to alcohol cues (51 % female; mean age=33.74). Participants reported how many drinks they would consume from $0-$80/drink following exposure to neutral and alcohol images in a fixed order. Participants purchased significantly more drinks in the alcohol compared to the neutral condition, which was also evident for demand indices (i.e., intensity, breakpoint, Omax, elasticity; ps<0.001; ds=0.46-0.92). Alcohol purchase decisions were associated with activation in rostral middle and medial frontal gyri, anterior insula, posterior parietal cortex, and dorsal striatum, among other regions. Activation was lower across regions in the alcohol relative to neutral cue condition, potentially due to greater automaticity of choices in the presence of alcohol cues or attenuation of responses due to fixed cue order. These results contribute to growing literature using neuroeconomics to understand alcohol misuse and provide a foundation for future research investigating decision-making effects of environmental alcohol triggers.

Longitudinal examination of alcohol demand and alcohol-related reinforcement as predictors of heavy drinking and adverse alcohol consequences in emerging adults

BACKGROUND AND AIMS

Behavioral economic theory predicts that high alcohol demand and high proportionate alcohol-related reinforcement are important determinants of risky alcohol use in emerging adults, but the majority of research to date has been cross-sectional in nature. The present study investigated prospective and dynamic relationships between alcohol demand and proportionate alcohol-related reinforcement in relation to heavy drinking days and alcohol problems.

DESIGN

Longitudinal cohort with assessments every 4 months for 20 months.

SETTING

Ontario, Canada.

PARTICIPANTS

Emerging adults reporting regular heavy episodic drinking (n = 636, Mage = 21.44; 55.8% female).

MEASUREMENTS

Heavy drinking days (HDD; Daily Drinking Questionnaire), alcohol problems (Brief Young Adult Alcohol Consequences Questionnaire), alcohol demand (Alcohol Purchase Task) and proportionate alcohol-related reinforcement (Activity Level Questionnaire).

FINDINGS

Linear mixed effects models revealed that behavioral economic indicators and alcohol-related outcomes significantly decreased over the study, consistent with 'aging out' of risky alcohol use. Random intercept cross-lagged panel models revealed significant between-person relationships, such that higher alcohol demand and alcohol-related reinforcement were positively associated with HDD and alcohol problems (random intercepts = 0.187-0.534, Ps < 0.01). Moreover, alcohol demand indicators (particularly the rate of change in elasticity of the demand curve, as measured by α, and the maximum expenditure, Omax) and proportionate alcohol-related reinforcement significantly forecasted changes in HDD at all time points (|βs| = 0.063-0.103, Ps < 0.05) in cross-lagged relationships, with bidirectional associations noted for the rate of change in elasticity (βs = -0.085 to -0.104, Ps < 0.01). Proportionate alcohol-related reinforcement also significantly forecasted changes in alcohol problems at all time points (βs = 0.072-0.112, Ps < 0.01).

CONCLUSIONS

Multiple behavioral economic indicators (demand elasticity, maximum expenditure and reinforcement ratio) forecast changes in heavy episodic drinking and alcohol problems over the course of emerging adulthood. These results further implicate alcohol demand and proportionate alcohol-related reinforcement as etiologically and developmentally important mechanisms in alcohol use trajectories.

Applying behavioral economics to understand changes in alcohol outcomes during the transition to adulthood: Longitudinal relations and differences by sex and race

OBJECTIVE

Population drinking trends show clear developmental periodicity, with steep increases in harmful alcohol use from ages 18 to 22 followed by a gradual decline across the 20s, albeit with persistent problematic use in a subgroup of individuals. Cross-sectional studies implicate behavioral economic indicators of alcohol overvaluation (high alcohol demand) and lack of alternative substance-free reinforcers (high proportionate alcohol-related reinforcement) as potential predictors of change during this developmental window, but longitudinal evidence is sparse.

METHOD

Using a sample of emerging adults (N = 497, Mage = 22.61 years, 62% female, 48.69% White, 40.44% Black), this study examined prospective, bidirectional relations between both past-week heavy drinking days (HDD) and alcohol problems and proportionate alcohol-related reinforcement (reinforcement ratio), alcohol demand intensity (consumption at zero price), alcohol demand Omax (maximum expenditure), and change in demand elasticity (rate of change in consumption across escalating price) over five assessments (every 4 months) using random intercept cross-lagged panel models.

RESULTS

Alcohol problems and HDD decreased across assessments. Significant between-person effects indicated that each behavioral economic variable was associated with increased drinking risk. Change in reinforcement ratio was positively associated with decreases in alcohol problems. Multigroup invariance modeling revealed distinct risk pathways in that change in demand intensity and Omax predicted change in alcohol problems for male participants and change in intensity predicted change in alcohol problems for non-White participants.

CONCLUSION

The study provides consistent support for proportionate alcohol-related reinforcement and mixed support for demand as within-person predictors of reductions in drinking. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Attention-deficit/hyperactivity disorder is associated with more alcohol problems and less substance-free reinforcement: A behavioral economics daily diary study of college student drinkers

OBJECTIVE

Behavioral economic theory suggests that alcohol risk is related to elevated alcohol reinforcing efficacy (demand) combined with diminished availability of reinforcing substance-free activities, but little research has examined these reward-related processes at the daily level in association with comorbid conditions that might influence behavioral patterns and reward. Young people with attention-deficit/hyperactivity disorder (ADHD) report high levels of risky drinking, and this risk may be due in part to elevated demand for alcohol and diminished engagement in enjoyable and valued substance-free activities.

METHOD

College student drinkers (N = 101; 48.5% female; 68.3% White; 18-22 years old) with (n = 51) and without (n = 50) ADHD completed 14 consecutive daily diaries (diary entry n = 1,414). We conducted a series of multilevel path models to examine (a) the associations among ADHD and average daily alcohol demand, substance-free enjoyment, and response contingent positive reinforcement (RCPR) for goal-directed behaviors; (b) the associations among concurrent daily alcohol demand, substance-free reinforcement, and RCPR for goal-directed behaviors and daily alcohol use and alcohol-related negative consequences; and (c) the moderating effect of ADHD on these within-day associations.

RESULTS

ADHD was significantly associated with more daily alcohol-related negative consequences and less daily substance-free enjoyment and RCPR. Regardless of ADHD status, there were significant associations among behavioral economic risk factors and alcohol use and negative consequences, though effects differed within and between persons. There were no moderating effects of ADHD on within-person associations.

CONCLUSIONS

Results expose areas of impairment specific to drinkers with ADHD and advance theory on ADHD and hazardous drinking. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Making decisions one drink at a time and the "just one drink" effect: A fuzzy-trace theory model of harmful drinking

BACKGROUND

Understanding the decision factors that drive harmful alcohol use among young adults is of practical and theoretical importance. We apply fuzzy-trace theory (FTT) to investigate a potential danger that may arise from the arguably correct notion that a single drink carries no meaningful risk. Decisions that are mentally represented as one drink at a time could contribute to excessive drinking.

METHODS

College students (N = 351) made a series of decisions to take or decline eight hypothetical drinks presented one at a time. Outcome measures included each decision, recent alcohol consumption (weekly drinks, peak blood alcohol content, and binges), and alcohol-related harms (scores on the Brief Young Adult Alcohol Consequences Questionnaire and Alcohol Use Disorders Identification Test). Linear regression models predicted each outcome from sex, perceived risk of a single drink, perceived risk of heavy drinking, perceived consequences of drinking, and general health-related risk sensitivity.

RESULTS

Consistent with FTT, decisions to have a first drink and up to four additional drinks in short succession were each associated with lower perceived risk of one drink-a "just-one drink" effect-independent of perceived risks of heavy drinking, perceived consequences of drinking, and general risk sensitivity. Similarly, all measures of recent alcohol consumption and consequent harms were associated with perceived risk of one drink. Participants reporting "zero risk" of a single drink had worse outcomes on all measures than those reporting at least "low risk."

CONCLUSIONS

Results are consistent with the theoretically informed premise that consumption decisions are typically made one drink at a time rather than by deciding the total number of drinks to be consumed in a sitting. When decisions about alcohol use proceed one drink at a time, a perception of zero risk in a single drink may contribute to heavy drinking.

An experimental investigation into the effect of negative affect on the behavioral economic demand for alcohol

Influential theoretical models hypothesize that alcohol use is an especially potent reinforcer when used as a strategy to cope with negative affect. Although the evidence for this idea in observational data is weak, some experimental evidence suggests that the behavioral economic demand for alcohol increases immediately following a negative emotional event. Because existing studies testing the effect of negative mood inductions on the demand for alcohol have several methodological limitations and do not take inter- and intraindividual variability into account, we developed an improved experimental design to increase our confidence in any potential within-person effect of negative mood inductions on alcohol demand as well as to test whether this effect exhibits systematic inter- and intraindividual variability. We hypothesize that people will show a higher demand for alcohol following negative compared to neutral mood inductions and that this effect is stronger in heavy compared to light drinkers as well as stronger on days characterized by higher coping motives and negative urgency. Three hundred twenty college students will complete the alcohol purchase task (APT) after being subjected to 100 mood inductions (six negative, six neutral) on 20 separate days. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Behavioral economic analysis of legal and illegal cannabis demand in Spanish young adults with hazardous and non-hazardous cannabis use

BACKGROUND

In October 2021, a legal framework that regulates cannabis for recreational purposes in Spain was proposed, but research on its potential impacts on cannabis use is currently limited. This study examined the reliability and discriminant validity of two Marijuana Purchase Tasks (MPTs) for measuring hypothetical legal and illegal cannabis demand, and to examine differences in demand of both commodities in young adults at hazardous vs. non-hazardous cannabis use risk levels.

METHODS

A total of 171 Spanish young adults [Mage = 19.82 (SD = 1.81)] with past-month cannabis use participated in a cross-sectional study from September to November 2021. Two 27-item MPTs were used to estimate hypothetical demand for legal and illegal cannabis independently. The Cannabis Use Disorder Identification Test (CUDIT-R) was used to assess hazardous cannabis use and test for discriminant validity of the MPTs. Reliability analyses were conducted using Classical Test Theory (Cronbach's alpha) and Item Response Theory (Item Information Functions).

RESULTS

The MPT was reliable for measuring legal (α = 0.94) and illegal (α = 0.90) cannabis demand. Breakpoint (price at which demand ceases), and Pmax (price associated with maximum expenditure) were the most sensitive indicators to discriminate participants with different levels of the cannabis reinforcing trait. No significant differences between legal and illegal cannabis demand in the whole sample were observed, but hazardous vs. non-hazardous users showed higher legal and illegal demand, and decreased Breakpoint and Pmax if cannabis were legal vs illegal.

CONCLUSION

The MPT exhibits robust psychometric validity and may be useful to inform on cannabis regulatory science in Spain.

A high-resolution PheWAS approach to alcohol-related polygenic risk scores reveals mechanistic influences of alcohol reinforcing value and drinking motives

AIMS

This study uses a high-resolution phenome-wide approach to evaluate the motivational mechanisms of polygenic risk scores (PRSs) that have been robustly associated with coarse alcohol phenotypes in large-scale studies.

METHODS

In a community-based sample of 1534 Europeans, we examined genome-wide PRSs for the Alcohol Use Disorders Identification Test (AUDIT), drinks per week, alcohol use disorder (AUD), problematic alcohol use (PAU), and general addiction, in relation to 42 curated phenotypes. The curated phenotypes were in seven categories: alcohol consumption, alcohol reinforcing value, drinking motives, other addictive behaviors, commonly comorbid psychiatric syndromes, impulsivity, and personality traits.

RESULTS

The PRS for each alcohol phenotype was validated via its within-sample association with the corresponding phenotype (adjusted R2s = 0.35-1.68%, Ps = 0.012-3.6 × 10-7) with the exception of AUD. All PRSs were positively associated with alcohol reinforcing value and drinking motives, with the strongest effects from AUDIT-consumption (adjusted R2s = 0.45-1.33%, Ps = 0.006-3.6 × 10-5) and drinks per week PRSs (adjusted R2s = 0.52-2.28%, Ps = 0.004-6.6 × 10-9). Furthermore, the PAU and drinks per week PRSs were positively associated with adverse childhood experiences (adjusted R2s = 0.6-0.7%, Ps = 0.0001-4.8 × 10-4).

CONCLUSIONS

These results implicate alcohol reinforcing value and drinking motives as genetically-influenced mechanisms using PRSs for the first time. The findings also highlight the value of dissecting genetic influence on alcohol involvement through diverse phenotypic risk pathways but also the need for future studies with both phenotypic richness and larger samples.

Using behavioral economics to optimize safer undergraduate late-night transportation

Many universities sponsor student-oriented transit services that could reduce alcohol-induced risks but only if services adequately anticipate and adapt to student needs. Human choice data offer an optimal foundation for planning and executing late-night transit services. In this simulated choice experiment, respondents opted to either (a) wait an escalating delay for a free university-sponsored "safe" option, (b) pay an escalating fee for an on-demand rideshare service, or (c) pick a free, immediately available "unsafe" option (e.g., ride with an alcohol-impaired driver). Behavioral-economic nonlinear models of averaged-choice data describe preference across arrangements. Best-fit metrics indicate adequate sensitivity to contextual factors (i.e., wait time, preceding late-night activity). At short delays, students preferred the free transit option. As delays extend beyond 30 min, most students preferred competing alternatives. These data depict a policy-relevant delay threshold to better safeguard undergraduate student safety.

Alcohol cues increase behavioral economic demand and craving for alcohol in nontreatment-seeking and treatment-seeking heavy drinkers

BACKGROUND

Behavioral economic research has revealed significant increases in alcohol demand following exposure to alcohol-related cues. Prior research has focused exclusively on nontreatment-seeking heavy drinkers, included only male participants, or used heterogeneous methods. The current studies sought to replicate and extend existing findings in treatment-seeking and nontreatment-seeking heavy drinkers while also examining sex effects and moderation by alcohol use disorder (AUD) severity.

METHODS

Study 1 included 117 nontreatment-seeking heavy drinkers (51.5% women; M age 34.69; 56.4% AUD+), and Study 2 included 89 treatment-seeking heavy drinkers with AUD (40.4% women; M age = 41.35). In both studies, alcohol demand was measured using a hypothetical alcohol purchase task (APT), and subjective alcohol craving was measured using visual analog scales. Measures were collected following exposure to neutral (water) cues in a standard room and alcohol cues in a bar lab.

RESULTS

Alcohol demand (intensity, Omax , breakpoint, and elasticity) and craving were significantly increased following alcohol cues compared to neutral cues (ps < 0.005) with effect sizes ranging from small to large (ηp 2  = 0.074-0.480). Participants with AUD (Study 1) or with higher AUD severity (Study 2) reported higher craving and higher demand for most indices (i.e., main effects; ps < 0.032, ηp 2  = 0.043-0.239). A larger alcohol cue increase in Omax was found for AUD+ participants in Study 1 compared to non-AUD participants (p = 0.028, ηp 2  = 0.041) but not for any other indices in Study 1 or Study 2. There were no significant sex effects.

CONCLUSIONS

These findings replicate and extend prior research by offering additional insight into alcohol cue effects on the reinforcing value of alcohol and subjective motivation to drink. The results also suggest that sex and AUD severity do not meaningfully impact cue effects across most indices of demand.

Reliability and validity of behavioral-economic measures: A review and synthesis of discounting and demand

This review sought to synthesize the literature on the reliability and validity of behavioral-economic measures of demand and discounting in human research, introduce behavioral-economic research methodologies for studying addictive behaviors, discuss gaps in the current literature, and review areas for future research. A total of 34 studies was included in this review. The discounting literature showed similar responding regardless of whether hypothetical or actual outcomes were used, though people tended to discount the outcome presented first more steeply, suggesting order effects. Although delay-discounting measures seem to show temporal stability, exceptions were found for probability- and experiential-discounting tasks. The demand literature also demonstrated similar responding regardless of outcome type; however, some demand indices showed exceptions. Randomized price sequences tended to show modest increases in Omax and α and modestly higher rates of inconsistent or nonsystematic responses compared with sequential price sequences. Demand indices generally showed temporal stability, although the stability was weaker the larger the time interval between test sessions. Future studies would benefit by examining addictive commodities beyond alcohol, nicotine, and money; examining temporal stability over longer time intervals; using larger delays in discounting tasks; and using larger sample sizes.

Associations between alcohol demand, delayed reward discounting, and high-intensity drinking in a diverse emerging adult sample

The high-intensity drinking threshold (HID; 8+/10+ drinks for women/men) is more strongly associated with significant alcohol-related health consequences than the more common heavy episodic drinking threshold (HED; 4+/5+ drinks for women/men). Behavioral economic measures of alcohol reward value (demand) and delayed reward discounting (DRD) have shown associations with other alcohol-related risk behaviors and may contribute to efforts to identify individuals who are at risk for HID from the larger subgroup of at-risk drinkers who engage in HED. Logistic regression analyses tested if alcohol demand and DRD were associated with HID in a sample of 477 emerging adults who reported recent heavy drinking. Receiver operating curve (ROC) analyses were conducted to test these variables' ability to classify HID group membership and to select an optimal cutoff score. In logistic regression analyses controlling for typical weekly drinking, demographics, and other variables associated with HID, participants reporting higher demand intensity (amount of alcohol purchased when price is zero; Adjusted Odds Ratio (AOR) = 20.27, 95% CI [5.71, 71.91]) and lower demand elasticity (sensitivity of alcohol consumption to increases in cost; AOR = .29, 95% CI [.11, 72]) were more likely to report HID relative to HED. Omax (maximum alcohol expenditure) and DRD were associated with HID in bivariate, but not in multivariate models. The ROC analysis provided support for an intensity cutoff of 7.5 or higher. These findings suggest that brief alcohol demand curve measures, in particular demand intensity and elasticity, may have utility in identifying individuals who are at risk for HID. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A new statistical model for binge drinking pattern classification in college-student populations

Background

Binge drinking (BD) among students is a frequent alcohol consumption pattern that produces adverse consequences. A widely discussed difficulty in the scientific community is defining and characterizing BD patterns. This study aimed to find homogenous drinking groups and then provide a new tool, based on a model that includes several key factors of BD, to assess the severity of BD regardless of the individual's gender.

Methods

Using the learning sample (N1 = 1,271), a K-means clustering algorithm and a partial proportional odds model (PPOM) were used to isolate drinking and behavioral key factors, create homogenous groups of drinkers, and estimate the probability of belonging to these groups. Robustness of our findings were evaluated with Two validations samples (N2 = 2,310, N3 = 120) of French university students (aged 18-25 years) were anonymously investigated via demographic and alcohol consumption questionnaires (AUDIT, AUQ, Alcohol Purchase Task for behavioral economic indices).

Results

The K-means revealed four homogeneous groups, based on drinking profiles: low-risk, hazardous, binge, and high-intensity BD. The PPOM generated the probability of each participant, self-identified as either male or female, to belong to one of these groups. Our results were confirmed in two validation samples, and we observed differences between the 4 drinking groups in terms of consumption consequences and behavioral economic demand indices.

Conclusion

Our model reveals a progressive severity in the drinking pattern and its consequences and may better characterize binge drinking among university student samples. This model provides a new tool for assessing the severity of binge drinking and illustrates that frequency of drinking behavior and particularly drunkenness are central features of a binge drinking model.

Next-day responsibilities attenuate demand for alcohol among a crowdsourced sample of community adults

While several studies have examined how class time and internship responsibilities impact demand for alcohol in undergraduate samples, no study has examined this question using more universally applicable responsibilities with a sample of community adults. Therefore, the aim of this study was to examine the impact of a range of next-day responsibilities on demand for alcohol among a crowdsourced sample of community adults using a hypothetical alcohol purchase task (APT). Community adults (n = 261; 79% White; 60% identified as men; 39% identified as women; and 1% identified as nonbinary) with a mean age of 38.42 recruited from Amazon Mechanical Turk rank-ordered eight hypothetical next-day responsibilities across three categories (i.e., work, caregiving, and recreational). Participants first completed a standard APT with no explicit next-day responsibilities, followed by purchase tasks in the context of their two highest ranked responsibilities. All participants needed to pass several stages of attention and data quality checks to be included in the final sample. All observed demand indices (i.e., intensity, breakpoint, Omax, and Pmax) were significantly higher in the no responsibilities condition compared to both the first- and second-ranked responsibility condition (ps < .001); however, there was no significant difference in any demand index between the first- and second-ranked responsibility (p range .65-.91). These results extend prior work by demonstrating engagement with substance-free alternatives may reduce demand for alcohol among community adults. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Attempts to Influence the Value of Alcohol by Manipulating Social Influence and Context

Background: Recent cognitive neuroscience models of value-based decision-making suggest value-based choices for alcohol are sensitive to various inputs, such as context and social influence. In two online experiments, we tested whether manipulating these inputs influenced proxies for alcohol value. Experiment 1: 157 social drinkers were presented with 4 hypothetical scenarios (drinking alone, with friends who are also drinking, with friends but trying to "cut-down" for health reasons, with friends who aren't drinking) in a within-subjects design, and completed the Brief Assessment of Alcohol Demand after each as a measure of value. Value for alcohol (number of drinks purchased) was greatest when drinking with friends who were also drinking compared to drinking alone (d = 0.95), friends not drinking (d = 1.49) and friends drinking/health related (d = 1.59). Value for alcohol was also greater when drinking alone compared to with friends who were not drinking (d = 0.55), and also with friends drinking/health related (d = 0.62). Experiment 2: 241 participants were randomly allocated to see one of four categories of images in a 2 (context: bar vs house) x 2 (social influence: enjoy vs not enjoy) design, before completing a Concurrent Choice Task for alcohol and Visual Analog Scales. There were no significant effects found on either task, both taken as proxies for value. Conclusion: There was inconclusive evidence that the value for alcohol could be manipulated by social context. This could be explained by greater saliency of the manipulation in asking participants to imagine themselves in a hypothetical situation as opposed to presenting images depicting drinking scenarios.

The Blinded-Dose Purchase Task: assessing hypothetical demand based on cocaine, methamphetamine, and alcohol administration

RATIONALE

Behavioral economic drug purchase tasks quantify the reinforcing value of a drug (i.e., demand). Although widely used to assess demand, drug expectancies are rarely accounted for and may introduce variability across participants given diverse drug experiences.

OBJECTIVES

Three experiments validated and extended previous hypothetical purchase tasks by using blinded drug dose as a reinforcing stimulus, and determined hypothetical demand for experienced effects while controlling for drug expectancies.

METHODS

Across three double-blind, placebo-controlled, within-subject experiments, cocaine (0, 125, 250 mg/70 kg; n=12), methamphetamine (0, 20, 40 mg; n=19), and alcohol (0, 1 g/kg alcohol; n=25) were administered and demand was assessed using the Blinded-Dose Purchase Task. Participants answered questions regarding simulated purchasing of the blinded drug dose across increasing prices. Demand metrics, subjective effects, and self-reported real-world monetary spending on drugs were evaluated.

RESULTS

Data were well modeled by the demand curve function, with significantly higher intensity (purchasing at low prices) for active drug doses compared to placebo for all experiments. Unit-price analyses revealed more persistent consumption across prices (lower α) in the higher compared to lower active dose condition for methamphetamine (a similar non-significant finding emerged for cocaine). Significant associations between demand metrics, peak subjective effects, and real-world spending on drugs also emerged across all experiments.

CONCLUSIONS

Orderly demand curve data revealed differences across drug and placebo conditions, and relations to real-world measures of drug spending, and subjective effects. Unit-price analyses enabled parsimonious comparisons across doses. Results lend credence to the validity of the Blinded-Dose Purchase Task, which allows for control of drug expectancies.

Concurrent validity of the marijuana purchase task: a meta-analysis of trait-level cannabis demand and cannabis involvement

BACKGROUND AND AIMS

The Marijuana Purchase Task (MPT) is increasingly used to measure cannabis reinforcing value and has potential use for cannabis etiological and regulatory research. This meta-analysis sought to evaluate for the first time the MPT's concurrent validity in relation to cannabis involvement.

METHODS

Electronic databases and pre-print repositories were searched for MPT studies that examined the cross-sectional relationship between frequency and quantity of cannabis use, problems, dependence, and five MPT indicators: intensity (i.e. unrestricted consumption), Omax (i.e. maximum consumption), Pmax (i.e. price at which demand becomes elastic), breakpoint (i.e. first price at which consumption ceases), and elasticity (i.e. sensitivity to rising costs). Random effects meta-analyses of cross-sectional effect sizes were conducted, with Q tests for examining differences by cannabis variables, meta-regression to test quantitative moderators, and publication bias assessment. Moderators included sex, number of MPT prices, variable transformations, and year of publication. Populations included community and clinical samples.

RESULTS

The searches yielded 14 studies (n = 4077, median % females: 44.8%: weighted average age = 29.08 [SD = 6.82]), published between 2015 and 2022. Intensity, Omax , and elasticity showed the most robust concurrent validity (|r's| = 0.147-325, ps < 0.014) with the largest significant effect sizes for quantity (|r| intensity = 0.325) and cannabis dependence (|r| Omax  = 0.320, |r| intensity = 0.305, |r| elasticity = 0.303). Higher proportion of males was associated with increased estimates for elasticity-quantity and Pmax -problems. Higher number of MPT prices significantly altered magnitude of effects sizes for Pmax and problems, suggesting biased estimations if excessively low prices are considered. Methodological quality was generally good, and minimal evidence of publication bias was observed.

CONCLUSIONS

The marijuana purchase task presents adequate concurrent validity to measure cannabis demand, most robustly for intensity, Omax , and elasticity. Moderating effects by sex suggest potentially meaningful sex differences in the reinforcing value of cannabis.

A contextualized reinforcer pathology approach to addiction

Behavioural economic accounts of addiction conceptualize harmful drug use as an operant reinforcer pathology, emphasizing that a drug is consumed because of overvaluation of smaller immediate rewards relative to larger delayed rewards (delay discounting) and high drug reinforcing value (drug demand). These motivational processes are within-individual determinants of behaviour. A third element of learning theory posits that harmful drug use depends on the relative constraints on access to other available activities and commodities in the choice context (alternative reinforcers), reflecting the substantial influence of environmental factors. In this Perspective, we integrate alternative reinforcers into the contemporary behavioural economic account of harmful drug use - the contextualized reinforcer pathology model - and review empirical literature across the translational spectrum in support of this model. Furthermore, we consider how increases in drug-related mortality and health disparities in addiction can be understood and potentially ameliorated via a contextualized reinforcer pathology model in which lack of alternative reinforcement is a major risk factor for addiction.

Cannabis Involvement and Demand in Frequent Concentrate Users Versus Predominantly Flower Users

OBJECTIVE

Cannabis concentrate products contain more of the intoxicating cannabinoid, tetrahydrocannabinol, than flower products and, thus, may produce greater harm. Indeed, concentrate use is associated with greater cannabis dependence and problems (e.g., anxiety) than flower use. Given this, continued examination of concentrate versus flower use differences on associations with various cannabis measures may be useful. These measures include behavioral economic demand for cannabis (i.e., its subjective reinforcing value), use frequency, and dependence.

METHOD

In the present study of 480 cannabis users, those who were frequent concentrate users (n = 176) were compared with predominantly flower users (n = 304) regarding the relationship of two latent drug demand metrics assessed by the Marijuana Purchase Task to cannabis use frequency (i.e., days of cannabis use) and cannabis dependence (i.e., Marijuana Dependence Scale scores).

RESULTS

Two previously observed latent factors emerged, based on confirmatory factor analysis: amplitude, reflecting maximum consumption, and persistence, reflecting cost insensitivity. Group comparisons showed that amplitude was greater among the concentrate versus flower group, but no difference was found for persistence. Further, using structural path invariance testing, the factors were differentially associated with cannabis use frequency across groups. Amplitude was positively associated with frequency for both groups, whereas persistence was negatively associated with frequency for the flower group. Neither factor was associated with dependence for either group.

CONCLUSIONS

Findings continue to indicate that the demand metrics, although distinct, can be parsimoniously condensed into two factors. In addition, method of administration (i.e., concentrate vs. flower use) may affect how demand for cannabis relates to frequency of use. Associations were notably stronger with frequency relative to dependence.

Validation of the Food Purchase Task (FPT) in a clinical sample of smokers with overweight and obesity

Obesity is a major health problem associated with disease burden and mortality. In this context, analyzing food as a powerful reinforcer from a behavioral economics framework could be relevant for the treatment and prevention of obesity. The purposes of this study were to validate a food purchase task (FPT) in a clinical sample of Spanish smokers with overweight and obesity and to assess the internal structure of the FPT. We also analyzed the clinical utility of single-item breakpoint (i.e., commodity price that suppresses demand). A total of 120 smokers [% females: 54.2; M_age = 52.54; SD = 10.34] with overweight and obesity completed the FPT and weight/eating-related variables. Principal component analysis was used to examine the FPT structure, and a set of correlations were used to examine the relationship between the FPT, eating and weight-related variables. The FPT demonstrated robust convergent validity with other measures of eating. Higher food demand was related to higher food craving (r = .33), more binge eating problems (r = 0.39), more weight gain concerns (r = 0.35), higher frequency of both controlled (r = 0.37) and uncontrolled (r = 0.30) grazing, as well as to an eating style in response to emotions (r = 0.34) and external eating (r = 0.34). Of the demand indices, Intensity and O_max showed the highest magnitudes of effects. The FPT factors, persistence and amplitude, do not improve individual FPT indices; and the single-item breakpoint was not related to any eating or weight variable. The FPT is a valid measure of food reinforcement with potential clinical utility in smokers with obesity/overweight.

Notes on demand: Conceptual and empirical benefits of applying Rachlin's discounting equation to demand data

OBJECTIVE

Howard Rachlin wrote extensively on how value diminishes in a hyperbolic form, and he contributed to understanding choice processes between different commodities as a molar pattern of behavior. The field of behavioral economic demand has been dominated by exponential decay functions, indicating that decreases in consumption of a commodity are best fit by exponential functions. Because of the success of Rachlin's equation at describing how hyperbolic decay affects the value of a commodity across various factors (e.g., delay, probability, social distance), we attempted to extend his equation to behavioral economic demand data for alcohol and opioids.

METHOD

Rachlin's discounting equation was applied to estimate consumption on alcohol purchase task data and nonhuman drug demand data. We compared results of his equation to the exponentiated demand equation using both a mixed-effects modeling approach and a two-stage approach.

RESULTS

Rachlin's equation provided better fits to consumption data than the exponentiated equation for both mixed-effects and two-stage modeling. We also found that traditional demand metrics, such as Pmax, can be derived analytically when using Rachlin's equation. Certain metrics derived from Rachlin's equation appeared to be related to clinical covariates in ways similar to the exponentiated equation.

CONCLUSIONS

Rachlin's equation better described demand data than did the exponentiated equation, indicating that demand for a commodity may decrease hyperbolically rather than exponentially. Other benefits of his equation are that it does not have the same pitfalls as the current exponential equations and is relatively straightforward in its conceptualization when applied to demand data. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Interest in and perceived effectiveness of contingency management among alcohol drinkers using behavioral economic purchase tasks

Contingency management (CM), in which financial incentives are provided upon verification of abstinence from alcohol, cigarettes, and/or illicit substances, is one of the most highly effective and empirically supported treatments for substance use disorders. However, the financial cost of implementation has been identified as a major barrier to implementation of this treatment. The purpose of this study was to develop behavioral economic purchase tasks to assess interest in CM as a function of treatment cost and perceived effectiveness of CM as a function of abstinence incentive size in alcohol drinkers. Alcohol drinkers recruited from Amazon Mechanical Turk (MTurk) completed behavioral economic purchase tasks measuring demand for CM based on targeted abstinence intervals and treatment effectiveness and alcohol use disorder severity assessments. Nonlinear mixed-effects modeling was used to fit demand curves and assess the relationship between individual characteristics and demand metrics for CM. Results reveal that participants reported higher probability of remaining abstinent from drinking when offered larger incentives and required larger incentives when duration of abstinence required to earn the incentive was increased. Additionally, willingness to pay for treatment increased as effectiveness of treatment increased. Abstinence interval and treatment effectiveness are important features to consider when developing effective CM for widespread use, as these variables affected participants' likelihood of being abstinent and their interest in treatment. Future work will validate these assessments with actual treatment outcomes and determine predictors of CM treatment effectiveness. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Substance-related cross-commodity purchase tasks: A systematic review

OBJECTIVE

In the context of behavioral economics, drug use is a choice to which an individual may allocate responding despite the presence of alternative response possibilities. To examine the demand for a drug in an environment in which other drugs or nondrug alternatives are present, researchers often use a cross-commodity purchase task. These tasks allow participants to make choices across several reinforcers at varied unit prices and may elucidate behavioral economic patterns of substitutability and complementarity. The objective of this study was to conduct a systematic review of cross-commodity purchase task studies with human participants.

METHOD

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we screened 46 full-text studies (from 456 total records obtained from PsycINFO and PubMed databases and reference list search), yielding a final sample of 35 studies.

RESULTS

The drug category with the largest number of studies assessed was tobacco and nicotine products. The most consistent economic relationships found were substitutability of traditional cigarettes by e-cigarettes and e-liquid, and both legal and illegal cannabis for the other; however, other substitutable and complementary relationships were observed (e.g., substitution of food for cigarettes, a complementary relationship between alcohol and cannabis).

CONCLUSIONS

We discuss the implications of the results of this review from a treatment and harm reduction standpoint, highlight areas for future research particularly among drug categories with few studies and evaluating ecological validity of hypothetical measures, and make best practice recommendations for future cross-commodity drug-related purchase task research. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Hyperbolic discounting and exponentiated demand: Modeling demand for cigarettes in three dimensions

Behavioral economics has been a fruitful area of research in substance use. Mathematical descriptions of how individuals temporally discount the value of a commodity have been correlated with substance use and mathematical descriptions of drug consumption decreasing as a function of price (i.e., demand) predict maladaptive substance use. While there is a logical assumption that temporal factors affect demand for a drug, little has been done to merge these models. Thus, the purpose of this study was to combine models of discounting and demand, extending Howard Rachlin's work and contributions to novel areas of study. Data from 85 participants from Amazon Mechanical Turk (MTurk) who completed a hypothetical cigarette purchase task that included price of and delay to cigarettes were analyzed. Multilevel modeling was used to determine descriptive accuracy of combined additive and multiplicative models of discounting and demand. Of the discounting models used in conjunction with the exponentiated demand equation, the Rachlin hyperboloid best described the delay dimension of consumption. The multiplicative version of the Rachlin equation applied to both delay and price outperformed other models tested. Therefore, existing models of discounting and demand can be extended to modeling consumption data from complex multidimensional experimental arrangements.

Hazardous drinking and alcohol use disorders

Alcohol is one of the most widely consumed psychoactive drugs globally. Hazardous drinking, defined by quantity and frequency of consumption, is associated with acute and chronic morbidity. Alcohol use disorders (AUDs) are psychiatric syndromes characterized by impaired control over drinking and other symptoms. Contemporary aetiological perspectives on AUDs apply a biopsychosocial framework that emphasizes the interplay of genetics, neurobiology, psychology, and an individual's social and societal context. There is strong evidence that AUDs are genetically influenced, but with a complex polygenic architecture. Likewise, there is robust evidence for environmental influences, such as adverse childhood exposures and maladaptive developmental trajectories. Well-established biological and psychological determinants of AUDs include neuroadaptive changes following persistent use, differences in brain structure and function, and motivational determinants including overvaluation of alcohol reinforcement, acute effects of environmental triggers and stress, elevations in multiple facets of impulsivity, and lack of alternative reinforcers. Social factors include bidirectional roles of social networks and sociocultural influences, such as public health control strategies and social determinants of health. An array of evidence-based approaches for reducing alcohol harms are available, including screening, pharmacotherapies, psychological interventions and policy strategies, but are substantially underused. Priorities for the field include translating advances in basic biobehavioural research into novel clinical applications and, in turn, promoting widespread implementation of evidence-based clinical approaches in practice and health-care systems.

Behavioral economics indices predict alcohol use and consequences in young men at 4-year follow-up

BACKGROUND AND AIMS

The alcohol purchase task (APT), which presents a scenario and asks participants how many drinks they would purchase and consume at different prices, generates indices of alcohol reward value that have shown robust associations with alcohol-related outcomes in numerous studies. The aim was to test its prospective validity at 4-year follow-up.

DESIGN

Prospective cohort study.

SETTING

General population sample of young Swiss men.

PARTICIPANTS

A total of 4594 Swiss young men (median age = 21, 25th - 75th quartiles = 20.5 - 21.5) completed baseline questionnaires; among those, 4214 (91.7%) were successfully followed-up 4 years later.

MEASUREMENTS

Alcohol reward value parameters (i.e. intensity, the planned consumption when drinks are free; breakpoint, the price at which consumption would be suppressed; O_max , the maximum alcohol expenditure; P_max , the price associated with O_max ; and elasticity, the relative change in alcohol consumption as a function of the relative change in price) were derived from the APT at baseline and used to predict self-reported weekly drinking amount, monthly binge drinking, alcohol-related consequences and DSM-5 alcohol use disorder criteria.

FINDINGS

Regression analyses, adjusting for the baseline alcohol measure, age, linguistic region and socio-economic indicators showed that intensity, breakpoint, O_max and elasticity significantly predicted all tested outcomes in the expected direction (e.g. standardized incidence rate ratio [95% confidence interval] = 1.11 [1.07-1.15], 1.07 [1.03-1.10], 1.08 [1.04-1.11], and 0.92 [0.89-0.95], respectively, for weekly drinking amount, all P < 0.001). P_max did not significantly predict any outcomes. Non-adjusted correlations, baseline adjusted regression and ancillary analyses using (1) latent alcohol variables, (2) multiple imputation for missing data and (3) replications in training and testing subsamples to evaluate predictive accuracy provided consistent findings.

CONCLUSIONS

The alcohol purchase task demand curve measures of alcohol reward value are useful in characterizing alcohol-related risk in young men and have long-term predictive utility.

Change in alcohol demand following a brief intervention predicts change in alcohol use: A latent growth curve analysis

BACKGROUND

The association between behavioral economic demand and various alcohol use outcomes is well established. However, few studies have examined whether changes in demand occur following a brief alcohol intervention (BAI), and whether this change predicts alcohol outcomes over the long term.

METHODS

Parallel process piecewise latent growth curve models were examined in a sample of 393 heavy drinking emerging adults (60.8% women; 85.2% white; M_age  = 18.77). In these models, two linear slopes represented rates of change in alcohol use, heavy drinking episodes, alcohol-related problems, and demand (intensity and highest expenditure across all price points or O_max ) from baseline to 1 month (slope 1) and 1 month to 16 months (slope 2). Mediation analyses were conducted to estimate the effect of a BAI on 16-month alcohol outcomes through slope 1 demand.

RESULTS

A two-session BAI predicted significant reductions in all five outcomes from baseline to 1-month follow-up. Although no further reduction was observed from the 1-month to the 16-month follow-up, there was no regression to baseline levels. Slope 1 demand intensity, but not O_max , significantly mediated the association between BAI and both outcomes-heavy drinking episodes (Est. = -0.23, SE = 0.08, p < 0.01) and alcohol-related problems (Est. = -0.15, SE = 0.07, p < 0.05)-at the 16-month follow-up.

CONCLUSIONS

Reducing high valuation of alcohol among heavy drinking emerging adults within the first month following BAI is critical for the long-term efficacy of the intervention. A two-session BAI was associated with enduring reductions in alcohol demand, and the change in demand intensity, but not O_max , was associated with sustained reductions in heavy drinking and alcohol-related problems.

Alcohol demand as a predictor of drinking behavior in the natural environment

BACKGROUND AND AIMS

Alcohol demand, a measure of alcohol's reinforcing value, is associated with greater alcohol consumption and alcohol-related problems. Although alcohol demand has primarily been evaluated as a 'trait-like', individual difference measure, recent evidence indicates that demand exhibits meaningful short-term fluctuations. We aimed to determine whether moment-to-moment fluctuations in alcohol demand in individuals' natural drinking environments predicted drinking occurrence, drinking continuation, and drinking quantity.

DESIGN

Observational study.

SETTING

Individuals' natural drinking environments in Columbia, Missouri, USA.

PARTICIPANTS

Eighty-nine young adults (56% female; mean age = 24.8) participated from November 2018 to October 2020. Participants reported 14.5 drinking days [standard deviation (SD = 8.1)] and 4.1 drinks per occasion (SD = 2.5) during ecological momentary assessment (EMA).

MEASUREMENTS

Participants completed the alcohol purchase task at baseline. Following this, participants reported on their alcohol demand (breakpoint, O_max , intensity) and drinking behavior during EMA at daily, timed prompts from 6 p.m. to 2 a.m. They provided breathalyzer samples using a BACtrack Mobile® Pro. Models tested concurrent and prospective (lagged) associations between alcohol demand and drinking occurrence and drinking continuation after drinking initiation. Additional models tested concurrent associations between demand and breath alcohol concentrations (BrACs).

FINDINGS

Higher alcohol demand was associated with higher odds of drinking and continued drinking for all demand indices at the momentary [odds ratio (OR) = 1.27-1.56, ps ≤ 0.03] and day-level (OR = 2.14-3.39, ps < 0.001). Additionally, lagged demand predicted higher odds of drinking occurrence and continuation at the following prompt (OR = 1.32-1.53, ps ≤ 0.004). Higher alcohol demand was associated with higher BrACs at the momentary (bs = 0.0011-0.0026, ps ≤ 0.03) and day-level (bs = 0.0053-0.0062, ps < 0.001). At the person-level, findings varied depending on the demand measure.

CONCLUSIONS

Alcohol demand appears to be associated with both when and how much individuals drink in their natural drinking environments. Elevations in alcohol demand appear to be associated with increased likelihood of drinking and continuing to drink, and greater total alcohol consumption, both within and across drinking days.

Open trial of a personalized feedback intervention and substance-free activity supplement for veterans with PTSD and hazardous drinking

This study reports findings from an open trial of a two-session intervention for veterans with symptoms of PTSD and hazardous drinking. Rooted in behavioral economic theory, this intervention aimed to decrease alcohol use and increase alcohol-free activities through personalized and normative feedback. This trial assessed the feasibility and acceptability of the intervention in a sample of 15 veterans. Participants completed assessments at baseline and post-intervention (1-month and 3-months). Thirteen participants (86.6%) were retained between the baseline assessment and second intervention session. Acceptability data indicated that veterans overwhelmingly viewed the intervention positively with little dropout between the two sessions. Further, participants in our study reduced alcohol consumption from 37.30 (SD = 17.30) drinks per week at baseline to 22.50 (SD = 27.75) drinks per week at the 1-month assessment and then to 14.60 (SD = 18.64) at the 3-months assessment, representing medium to large effects. PTSD severity also decreased from 57.20 (SD = 16.72) at baseline to 48.90 (SD = 18.99) at the 1-month assessment, representing a small effect. Though effect sizes from pilot trials should be interpreted with caution, findings suggest that this intervention was well-received, feasible to deliver, and may have resulted in improvements in intervention targets.

The behavioral economics of alcohol demand in Greek-affiliated college students

BACKGROUND

College students affiliated with fraternity and sorority, or "Greek" life represent a known high-risk group for alcohol consumption and related consequences, but little is known about demand for alcohol in this population. The current study examined behavioral economic demand for alcohol in a sample of Greek life-affiliated undergraduate students using the alcohol purchase task (APT) and a novel variation of the APT that included a fixed-price, nonalcoholic alternative (APT Choice).

METHODS

Participants (n = 229) completed the APT, APT Choice, Alcohol Use Disorders Identification Test (AUDIT), and Daily Drinking Questionnaire (DDQ). Group demand indices were calculated for the entire sample and then separately for participants who met or did not meet the legal drinking age (21+ or underage, respectively). Independent-sample t tests assessed whether there were any significant differences between the two age cohorts in the percent change in each behavioral economic index from the APT to APT Choice. Tests of correlation evaluated the construct validity of the demand indices from both hypothetical purchase tasks.

RESULTS

Descriptive statistics on alcohol use in this Greek-affiliated sample revealed "hazardous" drinking scores, with AUDIT-C scores exceeding the threshold of alcohol misuse. These measures were significantly correlated with demand indices from both APT conditions, and demand was inversely related to price; however, demand for alcohol was reduced when a nonalcoholic alternative was available. Both age cohorts reported a reduction in BP₁ (highest price of nonzero consumption) and an increase in α (rate of change in elasticity), but these changes were significantly greater among underage participants.

CONCLUSIONS

Although Greek life-affiliated students demonstrate high demand for alcohol, the concurrent availability of a nonalcoholic alternative reduces alcohol demand, particularly for underage students. These findings suggest that nonalcoholic options may enhance the effectiveness of increasing alcohol prices to reduce alcohol consumption among students at higher risk for alcohol use.

Applying Mixed-Effects Modeling to Behavioral Economic Demand: An Introduction

Behavioral economic demand methodology is increasingly being used in various fields such as substance use and consumer behavior analysis. Traditional analytical techniques to fitting demand data have proven useful yet some of these approaches require preprocessing of data, ignore dependence in the data, and present statistical limitations. We term these approaches "fit to group" and "two stage" with the former interested in group or population level estimates and the latter interested in individual subject estimates. As an extension to these regression techniques, mixed-effect (or multilevel) modeling can serve as an improvement over these traditional methods. Notable benefits include providing simultaneous group (i.e., population) level estimates (with more accurate standard errors) and individual level predictions while accommodating the inclusion of "nonsystematic" response sets and covariates. These models can also accommodate complex experimental designs including repeated measures. The goal of this article is to introduce and provide a high-level overview of mixed-effects modeling techniques applied to behavioral economic demand data. We compare and contrast results from traditional techniques to that of the mixed-effects models across two datasets differing in species and experimental design. We discuss the relative benefits and drawbacks of these approaches and provide access to statistical code and data to support the analytical replicability of the comparisons.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40614-021-00299-7.

No evidence of the clinical utility of single-item breakpoint to inform on tobacco demand in persons with substance use disorders

RATIONALE

Behavioral economics has shown that single-item demand indicators are promising for capturing crucial aspects of nicotine reinforcement. It is suggested that brief breakpoint measures perform comparably to full-length demand indices in characterizing nicotine dependence; however, there have been no thorough assessments of their validity in clinical settings.

OBJECTIVES

This study aimed to assess the validity and accuracy of a single-item breakpoint in informing on tobacco demand.

METHODS

The sample consisted of 88 treatment-seeking smokers (% males = 70.5%) enrolled in substance use treatment. Participants provided data on smoking characteristics and completed the Fagerström Test for Nicotine Dependence, a single-item breakpoint measure and a 14-item cigarette purchase task (CPT). Hierarchical regressions were performed to compare the predictive capability of a single-item breakpoint and full-length tobacco demand indicators in determining nicotine addiction severity.

RESULTS

The single-item breakpoint was significantly correlated with all indices stemmed from the CPT and both latent factors (all r values = .250-.368). Neither the brief breakpoint nor the full-length breakpoint significantly predicted nicotine dependence. After controlling for sex and smoking variables, factor 2 [β = .565, p < .001] and its observed variables Omax [β = .279, p = .006], 1/elasticity [β = .340, p = .001], and intensity [β = .551, p < .001], robustly predicted nicotine dependence severity.

CONCLUSIONS

Our findings do not support the validity of single-item breakpoint measures for characterizing nicotine dependence in substance users. In a bid to foster translational research, brief demand measures capturing Omax, intensity, and elasticity should be developed.