Effects of experimental income on demand for potentially real cigarettes

Synthetic contraceptive hormones occlude the ability of nicotine to reduce ethanol consumption in ovary-intact female rats

Rates of tobacco and alcohol use in women are rising, and women are more vulnerable than men to escalating tobacco and alcohol use. Many women use hormonal birth control, with the oral contraceptive pill being the most prevalent. Oral contraceptives contain both a progestin (synthetic progesterone) and a synthetic estrogen (ethinyl estradiol; EE) and are contraindicated for women over 35 years who smoke. Despite this, no studies have examined how synthetic contraceptive hormones impact this pattern of polysubstance use in females. To address this critical gap in the field, we treated ovary-intact female rats with either sesame oil (vehicle), the progestin levonorgestrel (LEVO; contained in formulations such as Alesse®), or the combination of EE+LEVO in addition to either undergoing single (nicotine or saline) or polydrug (nicotine and ethanol; EtOH) self-administration (SA) in a sequential use model. Rats preferred EtOH over water following extended EtOH drinking experience as well as after nicotine or saline SA experience, and rats undergoing only nicotine SA (water controls) consumed more nicotine as compared to rats co-using EtOH and nicotine. Importantly, this effect was occluded in groups treated with contraceptive hormones. In the sequential use group, both LEVO alone and the EE+LEVO combination occluded the ability of nicotine to decrease EtOH consumption. Interestingly, demand experiments suggest an economic substitute effect between nicotine and EtOH. Together, we show that chronic synthetic hormone exposure impacts nicotine and EtOH sequential use, demonstrating the crucial need to understand how chronic use of different contraceptive formulations alter patterns of polydrug use in women.

Using an experimental tobacco marketplace to pilot test the substitutability of JUUL e-cigarettes and other alternative nicotine and tobacco products for conventional cigarettes among vulnerable populations

The Experimental Tobacco Marketplace (ETM) is an online research marketplace where increasing the cost of cigarettes is used to investigate the substitutability of other fixed-price tobacco products such as electronic nicotine delivery systems (ENDS). The ETM is useful for modeling effects of potential policy changes on use of various concurrently available products. To our knowledge, the ETM has not been used to investigate substitutability of newer generation e-cigarettes or populations at increased risk for smoking, heavy smoking, nicotine dependence, and smoking-attributable adverse effects. In the current pilot study, participants were 30 adult daily smokers with socioeconomic disadvantage or comorbid psychiatric conditions (substance-use disorder or mental illness). In each session, cigarette prices increased ($0.12, $0.25, $0.50, $1.00. and $2.00 per cigarette) while prices for alternative products remained fixed. Across three ETM sessions, either all products, all products except little cigars and cigarillos (LCCs), or all products except ENDS (JUUL e-cigarettes) were available. Linear regression was performed on individual participant data using log-transformed cigarette price to determine demand and substitution. Cigarette demand decreased as price increased across sessions (significantly non-zero slopes, ps ≤ 0.0001). When all products were available, ENDS substitution increased as cigarette price increased (significantly non-zero slope, p = .016). When LCCs were unavailable, ENDS again were a significant substitute (p = .008). When ENDS were unavailable, LCCs did not substitute (ps ≥ 0.48). In all sessions, participants rarely purchased other products (e.g., snus). Overall, ENDS were the most robust substitute for cigarettes, further underscoring the potential importance of ENDS availability on the impact of tobacco regulatory policies.

Behavioral economic demand modeling chronology, complexities, and considerations: Much ado about zeros

Behavioral economic demand has been shown to have high utility in quantifying the value or consumption of a commodity. Demand describes the relationship between cost and consumption of a commodity, and tends to be curvilinear with consumption approaching zero as the cost increases to a sufficiently high cost to suppress consumption completely. Over a period spanning greater than three decades, behavioral economists have made great strides in the modeling of demand and addressing analytical challenges, although this work is not complete and unresolved challenges remain. The analytical challenges associated with modeling zeros both when they arise as consumption values of zero and when consumption at zero cost is assessed have been a substantial part of this evolution in models. The goals of this methodological review are to provide a historical overview of the major behavioral economic demand models that have been proposed, describe some of the common difficulties with analyzing behavioral economic demand, and discuss general considerations for the analysis of demand. In an environment with evolving and multiple competing analytical practices, we conclude that researchers can maximize scientific rigor by embracing transparency in their analysis choices and employing techniques such as sensitivity analyses to determine if their analysis choices impact the conclusions of their experiments.

Behavioral economics of substance use: Understanding and reducing harmful use during the COVID-19 pandemic

Behavioral economic research demonstrates that alcohol and drug consumption is (a) an inverse function of constraints on access to the substance and (b) a direct function of constraints on access to alternative rewards. Physical distancing interventions and economic consequences of the COVID-19 pandemic have resulted in unprecedented reductions in many of the constraints on substance use and in critical evolutionarily salient sources of alternative reward, such as social interaction, physical activity, leisure activities and hobbies, and academic and occupational pursuits. Thus, behavioral economics suggests that the pandemic and necessary public health response have created a "perfect storm" for exacerbation of individual-level and population-level substance use problems and also points to multilevel intervention strategies. We summarize this perspective and research by highlighting 3 critical behavioral processes that will influence drug and alcohol consumption. First, the sudden absence of many effective constraints on substance use (work, school, community, or service obligations) will reduce the actual and perceived cost of use. Second, physical distancing measures will reduce the availability, and increase the cost, of many rewarding substance-free activities and commodities. Third, increased uncertainty around current and future events increases discounting of delayed rewards. These effects will be especially pernicious among populations with existing health disparities. Next, we outline interventions suggested by behavioral economics to mitigate the impact of COVID-19 on substance use that are aimed at increasing perceived costs of use; increasing access to substance-free activities, including treatment; and lengthening the timeframe for behavioral allocation and altering environmental contexts to promote healthy choices. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Illegal Experimental Tobacco Marketplace I: Effects of Vaping Product Bans

OBJECTIVES

Banning vaping products may have unintended outcomes, such as increased demand for illegal products. This study experimentally examined the effects of a vaping ban and a flavored vaping ban on the probability of purchasing illicit vaping products, and factors affecting purchasing from a hypothetical illegal marketplace.

METHODS

A crowdsourced sample of exclusive cigarette smokers, exclusive e-cigarette users, and frequent dual users (n = 150) completed hypothetical purchasing trials in an Experimental Tobacco Marketplace under three conditions (no ban, vaping ban, and flavored vaping ban). Participants chose to purchase in a hypothetical legal experimental tobacco marketplace (LETM) or illegal experimental tobacco marketplace (IETM). Vaping products were available in each marketplace depending on the condition. Other tobacco products were always available in the LETM. A hypothetical illicit purchase task with five fine amounts assessed the effect of monetary penalties.

RESULTS

Participants from all groups were more likely to purchase from the IETM when product availability in the LETM was more restricted, with e-cigarette users being most affected. The likelihood of purchasing illegal products was systematically decreased as monetary penalties associated with the IETM increased, with e-cigarette users showing greater persistence in defending their illicit purchases.

CONCLUSIONS

Restricting vaping products from the marketplace may shift preference towards purchasing vaping products in the illegal marketplace. Nevertheless, penalties imposed on consumer's behavior might be effective in preventing illicit trade. The IETM is a methodological extension that supports the utility and flexibility of the ETM as a framework for understanding the impact of different tobacco regulatory policies.

IMPLICATIONS

This study suggests that limiting or banning vaping products as a possible strategy to reduce the adverse effects of vaping products could result in some tobacco-users seeking banned products from illegal sources. Monetary fines were shown to reduce illegal purchases. Therefore, policymakers should consider implementing strategies that may mitigate illegal purchases.

Estimating the Impact of Tobacco Parity and Harm Reduction Tax Proposals Using the Experimental Tobacco Marketplace

Taxes are a demonstrably effective method to suppress tobacco use. This study examined the effects of the tobacco parity (i.e., imposing taxes equally on all tobacco products) and the harm reduction (i.e., applying taxes in proportion to the products' levels of harm) tax proposals on demand and substitution across products. A crowdsourced sample of cigarette smokers (n = 35) completed purchasing trials with increasing tax magnitudes across different tax tiers in the Experimental Tobacco Marketplace in a repeated-measures design. Products were placed in three tax tiers (high, medium, and no tax) according to each proposal's goal. The results indicated that total nicotine (mg) purchased was not significantly different between the proposals, with higher taxes yielding lower demand. However, as taxes increased, the tobacco parity proposal decreased the purchasing of all tobacco products and increased the purchasing of medicinal nicotine (i.e., the no tax tier). Conversely, the harm reduction proposal resulted in greater purchases of electronic nicotine delivery systems and smokeless tobacco (i.e., the medium tax tier). These findings support tobacco taxation as a robust tool for suppressing purchasing and suggest that differential taxation in proportion to product risk would be an effective way to incentivize smokers to switch from smoked to unsmoked products. Further studies should investigate the unintended consequences of their implementation.

Effects of Reduced-Nicotine Cigarettes Across Regulatory Environments in the Experimental Tobacco Marketplace: A Randomized Trial

INTRODUCTION

Cigarette smoking remains the leading preventable cause of death in the United States. Recent efforts have explored the potential health and policy benefits of reducing nicotine, an addictive component, in combustible cigarettes. To date, an experimental, prospective analysis directly comparing the effects of varying regulatory environments on purchases of multiple products has yet to be conducted. The present study compared real purchasing of conventional cigarettes, reduced-nicotine cigarettes, and a variety of other nicotine and tobacco products across a range of regulatory environments.

METHODS

Participants were assigned to one of five groups, each associated with a different nicotine level (mg of nicotine to g of tobacco) in SPECTRUM investigational cigarettes (15.8, 5.2, 2.4, 1.3, and 0.4 mg/g). Across sessions, participants made real purchases for nicotine/tobacco products in an Experimental Tobacco Marketplace. Each session corresponded with a distinct regulatory environment wherein different nicotine/tobacco products were available for purchase.

RESULTS

Our results suggest that the primary drivers of cigarette and nicotine purchasing are regulatory environment and the presence/absence of alternative nicotine and tobacco products. Perhaps surprisingly, nicotine level does not appear to be such a driver of purchasing behavior under these experimental conditions. Investigational cigarette purchasing is lowest when other preferred combustible products are available and highest when investigational cigarettes are the only combustible product available for purchase.

CONCLUSIONS

If a reduced-nicotine policy is implemented, great care should be taken in determining and making available less-harmful nicotine/tobacco products as the availability of preferred combustible products may result in undesirable levels of purchasing.

IMPLICATIONS

This is the first experimental study investigating different potential regulatory effects related to a reduced-nicotine policy by examining purchasing across a range of nicotine/tobacco products. Our results suggest the presence of affordable, highly preferred combustible products is likely to maintain tobacco purchasing at undesirable levels. To promote switching to less-harmful products, affordable alternate nicotine and tobacco products should be readily available. Finally, our results suggest that the availability of noncigarette products, not cigarette nicotine level, will most likely affect purchasing of reduced-nicotine cigarettes.

Knowledge, attitude, and implementation of nicotine replacement therapy by dental and medical interns in Davangere city: A cross-sectional survey

Background:

One of the prime causes of illness and premature death is smoking. Almost 50% of smokers attempt to quit the habit; however, at most, 2%–3% achieve success. The rationale is that innumerable withdrawal attempts are unplanned, and the most effective cessation aids are unacquainted. Nicotine replacement therapy (NRT) is the most common cessation aid. Furthermore, motivation from dental and medical professionals can be effective for patients to quit smoking. The study aimed to assess the knowledge, attitude, and practice regarding the implementation of NRT among dental and medical interns in Davangere city.

Materials and Methods:

A questionnaire-based survey was conducted, which included 442 dental and medical interns from two dental and two medical colleges in Davangere city, Karnataka. The questionnaire included multiple-choice questions regarding knowledge, attitude, and implementation of NRT. The response rate of interns was 93.67%.

Results:

Among dental and medical interns, there was no statistically significant difference in knowledge about NRT with P = 0.976 (P > 0.05). However, a statistically significant difference existed regarding attitude and implementation in the interns about NRT among dental and medical interns with P = 0.001 (P < 0.05). Among dental and medical interns, dental interns had a positive attitude and implementation toward NRT than medical interns.

Conclusion:

The overview implicated that the dental interns had better vision than medical interns; however, both the groups' comprehension concerning NRT is scanty and advocates education about the fundamentals of NRT either via workshop or by continuing dental education programs.

Behavioral economic measurement of cigarette demand: A descriptive review of published approaches to the cigarette purchase task

The cigarette purchase task (CPT) is a behavioral economic method for assessing demand for cigarettes. Growing interest in behavioral correlates of tobacco use in clinical and general populations as well as empirical efforts to inform policy has seen an increase in published articles employing the CPT. Accordingly, an examination of the published methods and procedures for obtaining these behavioral economic metrics is timely. The purpose of this investigation was to provide a review of published approaches to using the CPT. We searched specific Boolean operators (["behavioral economic" AND "purchase task"] OR ["demand" AND "cigarette"]) and identified 49 empirical articles published through the year 2018 that reported administering a CPT. Articles were coded for participant characteristics (e.g., sample size, population type, age), CPT task structure (e.g., price framing, number and sequence of prices; vignettes, contextual factors), and data analytic approach (e.g., method of generating indices of cigarette demand). Results of this review indicate no standard approach to administering the CPT and underscore the need for replicability of these behavioral economic measures for the purpose of guiding clinical and policy decisions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Latent Structure of the Cigarette Purchase Task Among Treatment-Seeking Smokers With Depression and Its Predictive Validity on Smoking Abstinence

INTRODUCTION

Research has recently shown that nicotine reinforcement is better characterized by a bifactorial latent structure: persistence (insensitivity to cigarette pricing) and amplitude (consumption at inexpensive prices). No study to date has examined its value as a predictor of abstinence. This study aimed to provide new evidence on the latent structure of the cigarette purchase task (CPT) in smokers with depressive symptoms and to examine whether the latent structure performs better as a predictor of continuous abstinence than do the individual indices.

METHODS

Participants (n = 205 smokers; 72% female: Beck Depression Inventory, Second Edition, M = 24.68, SD = 10.45) were randomized to two smoking cessation treatments for quitting smoking: cognitive behavioral treatment (CBT) or CBT + contingency management (CM). A principal-components analysis was conducted to examine the latent structure of the CPT and a set of regression models were performed to assess its predictive validity.

RESULTS

The principal-components analysis revealed a bifactorial solution, which was interpreted as persistence (breakpoint, Omax, Pmax, and elasticity) and psychological inertia (intensity and elasticity of demand). Evidence on the convergent validity was obtained through significant associations between the two latent factors and smoking variables (all r values ≥.17). Psychological inertia was negatively related to the number of days of continuous abstinence at the end of treatment regardless of the treatment condition [R2 = .038; F(2, 202) = 4.989, p = .008].

CONCLUSIONS

Psychological inertia informs on which patients benefit less from smoking cessation treatments incorporating CM and CBT. Treatment components that affect individuals' excessive valuation of cigarettes might improve cessation outcomes.

IMPLICATIONS

This is the first attempt to examine the latent structure of the CPT in depressed smokers and to yield evidence on its predictive validity. A specific bifactorial solution exists for this population: persistence (breakpoint, Omax, Pmax, and elasticity) and psychological inertia (intensity and elasticity). Isolating demand indices and factors provides a high-resolution characterization of nicotine reinforcement for depressed smokers in that it informs on treatment response. Compared to the individual CPT indices, psychological inertia more effectively predicts which patients benefit most from either CM or CBT. Treatment components that affect individuals' excessive valuation of cigarettes (eg, episodic future thinking) should be integrated into smoking cessation treatments.

Behavioral economic demand as a unifying language for addiction science: Promoting collaboration and integration of animal and human models

The intersection of pharmacological, psychological, and economic theory within behavioral economics has helped advance an understanding of substance use disorder. A notable contribution of this approach is the conceptualization of reinforcement from a behavioral economic demand perspective. Demand analyses provide a multidimensional view of reinforcement in which distinct behavioral mechanisms are measured that impact decision making and drug consumption. This review describes the state of research on behavioral economic demand as a common language for addiction science researchers across varied model systems and stages of a translational continuum. We first provide an overview of the theoretical concepts and procedures used to evaluate demand in animal and human models. The potential for demand to serve as a common language for diverse research groups in psychopharmacology and addiction science (e.g., those evaluating neurobehavioral outcomes, medications development, clinical practice) is then described. An overview is also provided of existing empirical studies that, while small in number, suggest good linguistic and conceptual overlap between animal and human demand models when studying biological, environmental, and pharmacological individual difference vulnerabilities underlying drug-taking behavior. Refinement of methodological procedures and incorporation of more nuanced environmental features should help improve correspondence between animal and human demand studies as well as clinical translation of such findings. Our hope is that this review and commentary ultimately serves as inspiration for new collaborative efforts involving behavioral economic demand between animal and human researchers who share a common goal of improving substance use treatment outcomes and broader psychological wellbeing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Experimental manipulations of behavioral economic demand for addictive commodities: a meta-analysis

BACKGROUND AND AIMS

Reinforcing value, an index of motivation for a drug, is commonly measured using behavioral economic purchase tasks. State-oriented purchase tasks are sensitive to phasic manipulations, but with heterogeneous methods and findings. The aim of this meta-analysis was to characterize the literature examining manipulations of reinforcing value, as measured by purchase tasks and multiple-choice procedures, to inform etiological models and treatment approaches METHODS: A random-effects meta-analysis of published findings in peer-reviewed articles. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol, studies were gathered through searches in PsycINFO and PubMed/MEDLINE (published 22 May 2018). Searches returned 34 unique studies (aggregate sample n = 2402; average sample size = 68.94) yielding 126 effect sizes. Measurements included change (i.e. Cohen's d) in six behavioral economic indices (intensity, breakpoint, O_max , P_max , elasticity, cross-over point) in relation to six experimental manipulations (cue exposure, stress/negative affect, reinforcer magnitude, pharmacotherapy, behavioral interventions, opportunity cost).

RESULTS

Cue exposure (d range = 0.25-0.44, all Ps < 0.05) and reinforcer magnitude [d = 0.60; 95% confidence interval (CI) = 0.18, 1.01; P < 0.005] manipulations resulted in significant increases in behavioral economic demand across studies. Stress/negative affect manipulations also resulted in a small, significant increase in O_max (d = 0.18; 95% CI = 0.01, 0.34; P = 0.03); all other effect sizes for negative affect/stress were non-significant, albeit similar in size (d range = 0.14-0.18). In contrast, pharmacotherapy (d range = -0.37 to -0.49; Ps < 0.04), behavioral intervention (d = -0.36 to -1.13) and external contingency (d = -1.42; CI = -2.30, -0.54; P = 0.002) manipulations resulted in a significant decrease in intensity. Moderators (substance type) explained some of the heterogeneity in findings across meta-analyses.

CONCLUSIONS

In behavioral economic studies, purchase tasks and multiple-choice procedures appear to provide indices that are sensitive to manipulations found to influence motivation to consume addictive substances in field experiments.

The Experimental Tobacco Marketplace: Demand and Substitutability as a Function of Cigarette Taxes and e-Liquid Subsidies

INTRODUCTION

The experimental tobacco marketplace (ETM) approximates real-world situations by estimating the effects of several, concurrently available products and policies on budgeted purchasing. Although the effects of increasing cigarette price on potentially less harmful substitutability are well documented, the effects of other, nuanced pricing policies remain speculative. This study used the ETM as a tool to assess the effects of two pricing policies, conventional cigarette taxation and e-liquid subsidization, on demand and substitutability.

METHODS

During sampling periods, participants were provided 2-day samples of 24 mg/mL e-liquid, after which ETM purchase sessions occurred. Across two ETM sessions, conventional cigarettes were taxed or e-liquid was subsidized in combination with increasing cigarette price. The other four available products were always price constant and not taxed or subsidized.

RESULTS

E-liquid functioned as a substitute for conventional cigarettes across all conditions. Increasing cigarette taxation and e-liquid subsidization increased the number of participants for which e-liquid functioned as a substitute. Cigarette taxation decreased cigarette demand, by decreasing demand intensity, and marginally increased the initial intensity of e-liquid substitution, but did not affect the functions' slopes (substitutability). E-liquid subsidization resulted in large increases in the initial intensity of e-liquid substitution, but did not affect e-liquid substitutability nor cigarette demand.

IMPLICATIONS

24 mg/mL e-cigarette e-liquid was the only product to significantly substitute for cigarettes in at least one condition throughout the experiment; it functioned as a significant substitute throughout all four tax and all four subsidy conditions. Increasing cigarette taxes decreased cigarette demand through decreases in demand intensity but did not affect e-cigarette substitution. Increasing e-liquid subsidies increased e-liquid initial intensity of substitution but did not affect cigarette demand.

CONCLUSIONS

This study extended research on the behavioral economics of conventional cigarette demand and e-liquid substitutability in a complex marketplace. The results suggest that the most efficacious method to decrease conventional cigarette purchasing and increase e-liquid purchasing may involve greatly increasing cigarette taxes while also increasing the value of e-liquid through potentially less harmful product subsidization or differential taxation.

Behavioral economic demand and delay discounting are differentially associated with cigarette dependence and use in adolescents

INTRODUCTION

The Reinforcer Pathology Model describes how two behavioral economic processes, increased sensitivity to immediate rewards (delay discounting) and excessive reward derived from a substance (demand), both contribute to problematic patterns of substance use. In a novel application of this model, the current cross-sectional study examined how these distinct processes relate to different facets of cigarette use in adolescents.

METHODS

Adolescent daily cigarette smokers ages 15 to 19 (Mean age 17.7, N = 50) completed a laboratory assessment of demand using a Cigarette Purchase Task for their usual brand cigarettes and an adjusting-amount delay discounting task. Demand was conceptualized as two factors (Amplitude and Persistence) and delay discounting was calculated as Area Under the Curve (log AUC). The two factors of demand and discounting AUC were included as statistical predictors of level of cigarette dependence and average number of cigarettes smoked per day in linear regression models.

RESULTS

Amplitude of demand was marginally significant predictor (p = .06) of cigarettes smoked per day whereas neither Persistence of demand nor delay discounting significantly predicted this outcome. Both Amplitude of demand and delay discounting, but not Persistence, were associated with level of cigarette dependence. The effects of amplitude of demand and delay discounting on cigarette dependence or use did not significantly interact.

CONCLUSIONS

Results of this study suggest that amplitude of cigarette demand may be a risk factor for both cigarette consumption and dependence, while discounting - a known risk factor for cigarette initiation - may relate specifically to level of dependence.

Utilizing the commodity purchase task to evaluate behavioral economic demand for illicit substances: a review and meta-analysis

BACKGROUND ANDAIMS

The commodity purchase task is a simulated demand procedure that is easy and quick to complete (< 5 minutes) as well as adaptable for remote delivery and use with varied study populations. The purpose of this meta-analysis was to synthesize research using the commodity purchase task with illicit substances to evaluate the magnitude of omnibus effects sizes and moderators of the correlation of demand indices with quantity-frequency (QF) and severity measures.

DESIGN

Random-effects meta-analyses and meta-regressions involving studies with cross-sectional correlational designs.

SETTING AND PARTICIPANTS

Eleven studies, 10 outcomes and 2146 participants from two countries (USA and UK) published up to 1 October 2018.

MEASUREMENTS

Omnibus effect sizes (correlation coefficients) of five demand indices from the commodity purchase task [intensity (unconstrained consumption), elasticity (price sensitivity), O_max (maximum expenditure), P_max (price at maximum expenditure) and breakpoint (first price of zero consumption)] with QF and severity measures. Meta-regression models tested moderators of effect sizes (i.e. sample age and sex composition, commodity type and number of prices used in the commodity purchase task).

FINDINGS

Significant omnibus effect sizes were observed with QF and severity measures for intensity (r = 0.32/0.28, QF/severity, respectively), elasticity (r = -0.14/-0.18), O_max (r = 0.30/0.29) and breakpoint (r = 0.17/0.22) values. P_max was only significantly associated with severity measures (r = 0.15). The percentage of female participants and number of prices used in the purchase task significantly moderated P_max and breakpoint effect-size estimates in that stronger associations were observed in samples with a greater percentage of women and in studies using tasks with more price points. Commodity type (cannabis versus cocaine) did not significantly moderate associations involving any demand index.

CONCLUSIONS

Behavioral economic demand as measured by the commodity purchase task is consistently correlated with measures of illicit substance use quantity-frequency and severity.

Behavioral economic demand assessments in the addictions

Behavioral economics in the addictions is the application of both economics and psychology to study multifaceted components of substance use decision-making behavior. One such component is demand: the relative value of a substance for a user (i.e., the association between drug use and cost). The degree to which a user values a substance can be measured via performance on hypothetical purchase tasks which replicate drug purchase and consumption. Demand has been evaluated across substances, including alcohol, marijuana, tobacco, and alternative tobacco products. Recent advances in the study of demand have greatly improved the assessment of drug value, including application to novel products, selection of optimal task unit, assessment of demand in naïve or potential future users, and the importance of instructional set specificity.

Behavioral economic tobacco demand in relation to cigarette consumption and nicotine dependence: a meta-analysis of cross-sectional relationships

BACKGROUND AND AIMS

A cigarette purchase task (CPT) aims to characterize individual variation in the reinforcing value of tobacco. This meta-analysis estimated the associations between cigarette demand, tobacco consumption and nicotine dependence using this task.

DESIGN

A meta-analysis of cross-sectional studies identified by PubMed and PsycINFO databases was conducted. Fixed- and random-effects models were used. The study also examined the model used to derive elasticity of demand (exponential or exponentiated) as a potential moderator. Publication bias was assessed using 'fail-safe N', Begg-Mazumdar test, Egger's test, Tweedie's trim-and-fill approach and meta-regression of publication year with effect size.

SETTING

Studies from any setting that reported coefficient correlations on the tested associations.

PARTICIPANTS

Daily cigarette users (i.e. 5 to 38 cigarettes per day; n = 7649).

MEASUREMENTS

Cigarette consumption, nicotine dependence and five tobacco demand indicators: intensity (i.e. consumption at no cost), elasticity (i.e. sensitivity to rises in costs), Omax (maximum expenditure), Pmax (i.e. price at which consumption becomes elastic) and breakpoint (i.e. price at which consumption ceases).

FINDINGS

Twenty-three studies met inclusion criteria. All the CPT indices were significantly correlated with smoking behavior (rs = 0.044-0.572, Ps = 0.012-10-8 ). Medium-to-large effect size associations were present for intensity, Omax, and elasticity, whereas small effects were obtained for breakpoint and Pmax . Evidence of a moderating effect of the different elasticity modeling approaches was not present. There was limited evidence of publication bias.

CONCLUSIONS

All five demand indices derived from the cigarette purchase task by (CPT) were robustly associated with cigarette consumption and tobacco dependence. Of the demand indices, maximum expenditure, intensity and elasticity exhibited the largest magnitude associations.

The R package beezdemand: Behavioral Economic Easy Demand

beezdemand: Behavioral Economic Easy Demand, a novel package for performing behavioral economic analyses, is introduced and evaluated. beezdemand extends the statistical program to facilitate many of the analyses performed in studies of behavioral economic demand. The package supports commonly used options for modeling operant demand and performs data screening, fits models of demand, and calculates numerous measures relevant to applied behavioral economists. The free and open source beezdemand package is compared to commercially available software (i.e., GraphPad Prism™) using peer-reviewed and simulated data. The results of this study indicated that beezdemand provides results consistent with commonly used commercial software but provides a wider range of methods and functionality desirable to behavioral economic researchers. A brief overview of the package is presented, its functionality is demonstrated, and considerations for its use are discussed.

Validation of a brief behavioral economic assessment of demand among cigarette smokers

Basic and clinical addiction research use demand measures and analysis extensively to characterize drug use motivations. Hence, obtaining an accurate and brief measurement of demand that can be easily utilized in different settings is highly valued. In the current study, 2 versions of a breakpoint measure, designed to capture cigarette demand, were investigated in 119 smokers who were recruited from an online crowdsourcing platform. The first version determines the maximum price a smoker is willing to pay for one cigarette received right now when paid out of pocket, and the second determines the maximum price when paid using a hypothetical $100 gift card received for free. The breakpoint measures were administered along with the Cigarette Purchase Task (CPT), Fagerström Test for Cigarette Dependence (FTCD), and The Questionnaire of Smoking Urges (QSU-brief). Both single-item breakpoint versions were significantly correlated with CPT-derived demand measures loaded on the persistence factor (i.e., elasticity of demand, breakpoint, Pmax, and Omax), but not with those loaded on the amplitude factor (i.e., intensity of demand). In addition, both single-item measures were associated with metrics of tobacco dependence (e.g., FTCD, QSU) with effect sizes that are similar to the ones found between CPT-derived breakpoint and those same metrics. These findings suggest that the single-item breakpoint measure is a viable method for measuring demand that may provide a useful and efficient tool to capture crucial and distinct aspects of smoking. In addition, the breakpoint measures may help increase the utility of behavioral demand measures in novel research and clinical settings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Electronic cigarette substitution in the experimental tobacco marketplace: A review

The evolution of science derives, in part, from the development and use of new methods and techniques. Here, we discuss one development that may have impact on the understanding of tobacco regulatory science: namely, the application of behavioral economics to the complex tobacco marketplace. The purpose of this paper is to review studies that examine conditions impacting the degree to which electronic nicotine delivery system (ENDS) products substitute for conventional cigarettes in the Experimental Tobacco Marketplace (ETM). Collectively, the following factors constitute the current experimental understanding of conditions that will affect ENDS use and substitution for conventional cigarettes: increasing the base price of conventional cigarettes, increasing taxation of conventional cigarettes, subsidizing the price of ENDS products, increasing ENDS nicotine strength, and providing narratives that illustrate the potential health benefits of ENDS consumption in lieu of conventional cigarettes. Each of these factors are likely moderated by consumer characteristics, which include prior ENDS use, ENDS use risk perception, and gender. Overall, the ETM provides a unique method to explore and identify the conditions by which various nicotine products may interact with one another that mimics the real world. In addition, the ETM permits the efficacy of a broad range of potential nicotine policies and regulations to be measured prior to governmental implementation.

Understanding alcohol motivation using the alcohol purchase task: A methodological systematic review

BACKGROUND

The Alcohol Purchase Task (APT) is a behavioral economic assessment of alcohol demand (i.e., motivation for consumption during escalating levels of response cost) using simulated marketplace survey techniques. While the APT is often used and widely cited, to date, there has yet to be a systematic review elucidating the variability in administering and analyzing the APT. The purpose of the current paper is to address this knowledge gap in the literature by cataloging the various purchase task methodologies and providing recommendations and future areas of inquiry.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology was utilized (Prospero: No. CRD42017072159). Searches through Google Scholar, PsychINFO, PubMed, and SpringerLink databases identified 47 empirical articles referencing the use of an APT and published through the year 2016. Articles were coded for demographic and procedural characteristics, structural characteristics of the APT itself, and characteristics of data analysis.

RESULTS

Results indicate substantial variation within categories and suggest that there is no standard approach to administering the APT or analyzing the responses generated from it. The results underscore the need for researchers to report as much information as possible related to administration, instructions, price structuring, and analytical approach, as we found that many articles did not provide these details.

CONCLUSION

Enhancing the transparency of APT methods and analyses in published reports will aid in reproducibility as well as future meta-analytic studies of alcohol demand that could lead to the development of best-practice recommendations for this procedure.

Effects of Filter Ventilation on Behavioral Economic Demand for Cigarettes: A Preliminary Investigation

Introduction

The majority of cigarettes sold in the United States and abroad feature filter ventilation holes designed to dilute mainstream smoke. Although initially intended to produce a safer cigarette, data instead suggest that filter ventilation increases total harm from smoking. In the present study, we examined the effects of blocking ventilation holes on behavioral economic demand for cigarettes (i.e., consumption as a function of price).

Methods

In a within-subjects design, regular smokers (N = 15) of ventilated cigarettes sampled vent-blocked cigarettes for 3 days. Subsequently, they completed three sessions in which they used an experimental income to purchase vent-blocked and/or control cigarettes across a range of prices. Participants also completed the Drug Effects/Liking Scale.

Results

In sessions in which only one cigarette type was available, demand measures were undifferentiated between cigarette types. However, in sessions in which both cigarettes were available at equivalent prices, significantly greater preference for ventilated control cigarettes emerged in demand measures. Regardless of session type, participants also rated vent-blocked cigarettes more poorly in the Drug Effects/Liking Scale (more bad effects, fewer good effects, and less liking, desire, and less likely to use again).

Conclusions

Removing filter ventilation reduced cigarette abuse liability, as measured by behavioral economic demand and the Drug Effects/Liking Scale. However, reduced demand was only apparent when both cigarette types were concurrently available. This selective effect suggests that regulatory action banning filter ventilation would only reduce cigarette consumption when effective substitutes for vent-blocked cigarettes are available.

Implications

This preliminary study indicates that regulatory action designed to ban or restrict cigarette filter ventilation may decrease cigarette abuse liability as measured by both behavioral economic demand and self-report measures. However, effects of removing filter ventilation on demand measures appear to depend on concurrent availability of alternative, preferred cigarette types.

Cigarette and e-liquid demand and substitution in e-cigarette-naïve smokers

Behavioral economic methods allow experimental manipulation of price and examination of its effects on tobacco product purchasing. These methods may be used to examine tobacco product abuse liability and to prospectively model possible effects of price regulation. In the present study, we examined multiple measures of behavioral economic demand for cigarettes and e-liquid for use in a second-generation electronic cigarette (e-cigarette) in e-cigarette-naïve cigarette smokers. Twenty-five smokers received an e-cigarette (eGo ONE CT), sampled study e-liquid (24 mg/mL nicotine), and completed recurring sessions in which they used an experimental income to purchase real-world supplies of cigarettes and/or e-liquid. Participants also completed self-report measures of drug effects/liking. When products were available alone, we observed lower demand for e-liquid than for cigarettes. This effect was magnified when cigarettes and e-liquid were available concurrently. In additional assessments, e-liquid served as a partial substitute for cigarettes, but cigarettes did not serve as a substitute for e-liquid. Finally, participants rated e-liquid more poorly than cigarettes on several dimensions of drug effects/liking (any effects, liking, desire, and probability of continued use). We conclude that e-cigarette-naïve smokers value cigarettes more highly than e-liquid across multiple contexts and measurements. Nonetheless, participants still valued e-liquid positively and purchased it frequently, both as a substitute for cigarettes and independently of cigarettes. To understand the variables that influence transitions from exclusive smoking to either dual cigarette/e-cigarette use or exclusive e-cigarette use, future work should systematically examine the role of duration of e-liquid exposure. (PsycINFO Database Record

Experimental tobacco marketplace: substitutability of e-cigarette liquid for cigarettes as a function of nicotine strength

BACKGROUND

The experimental tobacco marketplace (ETM) provides a method to estimate, prior to implementation, the effects of new products or policies on purchasing across various products in a complex tobacco marketplace. We used the ETM to examine the relationship between nicotine strength and substitutability of alternative products for cigarettes to contribute to the literature on regulation of e-liquid nicotine strength.

METHODS

The present study contained four sampling and four ETM purchasing sessions. During sampling sessions, participants were provided 1 of 4 e-liquid strengths (randomised) to sample for 2 days followed by an ETM purchasing session. The nicotine strength sampled in the 2 days prior to an ETM session was the same strength available for purchase in the next ETM. Each participant sampled and could purchase 0 mg/mL, 6 mg/mL, 12 mg/mL and 24 mg/mL e-liquid, among other products, during the study.

RESULTS

Cigarette demand was unaltered across e-liquid strength. E-liquid was the only product to substitute for cigarettes across more than one e-liquid strength. Substitutability increased as a function of e-liquid strength, with the 24 mg/mL displaying the greatest substitutability of all products.

CONCLUSIONS

The present study found that e-liquid substitutability increased with nicotine strength, at least up to 24 mg/mL e-liquid. However, the effects of e-liquid nicotine strength on cigarette purchasing were marginal and total nicotine purchased increased as e-liquid nicotine strength increased.

The Experimental Tobacco Marketplace II: Substitutability and sex effects in dual electronic cigarette and conventional cigarette users

AIM

The aim of the current study was to evaluate tobacco product purchasing in the Experimental: Tobacco Marketplace (ETM) among male and female smokers who also use e-cigarettes. We hypothesized a high substitution profile for e-cigarettes and that males would purchase more Snus than females.

METHODS

The ETM is an online market used in clinical abuse liability research to mimic real-world purchasing patterns. Tobacco products, including each participant's usual choice of conventional and e-cigarettes, were presented along with a price and description of nicotine content. Participants were endowed with an account balance based on the number of cigarettes and e-cigarettes consumed per week. Each participant was exposed to four ETM sessions in random order during which the price of conventional cigarettes was manipulated.

RESULTS

Cigarette consumption decreased as price increased. A mixed factor three-way ANOVA revealed a significant main effect of price (i.e., more alternative products were purchased at higher cigarette prices), product (i.e., more e-cigarettes were purchased than gum, lozenges, and Snus), and sex (i.e., males purchased more than females). A significant three-way interaction indicated that males purchased more e-cigarettes, Snus, and dip than females at higher cigarette prices.

CONCLUSION

This study suggests that the user profile of cigarette smokers is associated with behavioral economic measures of alternative product substitution and indicates that the evaluation of nicotine replacement products should be considered for both males and females separately.

Progress of and Prospects for Hypothetical Purchase Task Questionnaires in Consumer Behavior Analysis and Public Policy

Based on the conceptual, methodological, and analytical framework of operant behavioral economics, hypothetical purchase task (HPT) questionnaires provide a low cost, scalable, and quantitatively rich source of empirical insights on consumer motivation, preferences, and decision-making. Here, we briefly summarize the history of HPT development and validation in clinically oriented research in addiction through to recent work with more conventional consumer goods and services. We discuss several possible novel applications of HPT methods to consumer behavior analysis for business, marketing, and public policy formulation and evaluation, as well as emerging best practices, limitations, and additional directions for future research and development.

Initial Development of an E-cigarette Purchase Task: A Mixed Methods Study

OBJECTIVES

Behavioral economic purchase tasks, which estimate demand for drugs, have been successfully developed for cigarettes and are widely used. However, a validated purchase task does not yet exist for e-cigarettes. The aim of this project was to identify the relevant units for an e-cigarette purchase task (E-CPT).

METHODS

Focus groups (N=28 participants in 7 groups, 2-7 participants per group) consisting of current e-cigarette users were conducted. Participants discussed their daily use patterns, completed a preliminary E-CPT which asked how many puffs of their e-cigarette they would consume per day at escalating prices, and discussed the extent to which the task accurately reflected their real-world behavior. Groups were recorded and transcribed; analysis focused on statements related to daily consumption and the E-CPT.

RESULTS

Participants were unlikely to quantify their daily use in terms of puffs, and perceptions about the appropriate unit for an E-CPT varied across device type. Users of first-generation devices (eg, cigalikes) reported that the relevant unit was the individual device/cartridge; however, participants who purchased nicotine liquid for their device emphasized that e-liquid volume in milliliters would better reflect their use.

CONCLUSIONS

Multiple versions of the E-CPT may be necessary to provide valid measures of e-cigarette demand.

Naturalistic assessment of demand for cigarettes, snus, and nicotine gum

RATIONALE

Behavioral economic measures of demand provide estimates of tobacco product abuse liability and may predict effects of policy-related price regulation on consumption of existing and emerging tobacco products.

OBJECTIVE

In the present study, we examined demand for snus, a smokeless tobacco product, in comparison to both cigarettes and medicinal nicotine. We used both a naturalistic method in which participants purchased these products for use outside the laboratory, as well as laboratory-based self-administration procedures.

METHODS

Cigarette smokers (N = 42) used an experimental income to purchase their usual brand of cigarettes and either snus or gum (only one product available per session) across a range of prices, while receiving all products they purchased from one randomly selected price. In a separate portion of the study, participants self-administered these products during laboratory-based, progressive ratio sessions.

RESULT

Demand elasticity (sensitivity of purchasing to price) was significantly greater for snus than cigarettes. Elasticity for gum was intermediate between snus and cigarettes but was not significantly different than either. Demand intensity (purchasing unconstrained by price) was significantly lower for gum compared to cigarettes, with no significant difference observed between snus and cigarettes. Results of the laboratory-based, progressive ratio sessions were generally discordant with measures of demand elasticity, with significantly higher "breakpoints" for cigarettes compared to gum and no significant differences between other study products. Moreover, breakpoints and product purchasing were generally uncorrelated across tasks.

CONCLUSIONS

Under naturalistic conditions, snus appears more sensitive to price manipulation than either cigarettes or nicotine gum in existing smokers.

Depressive Symptoms and Cigarette Demand as a Function of Induced Stress

INTRODUCTION

Depressed smokers may disproportionately value cigarettes as compared to other reinforcers in the context of increases in negative affect (NA). Thus, cigarette demand may be an important construct for understanding the relationship between depression, NA change, and tobacco use. The aim of the current study was to examine the interaction between depressive symptoms and change in NA as a function of induced mood as a predictor of cigarette demand.

METHODS

Participants included 73 young adult daily smokers (41.70% female, 73.60% White, age M (SD) = 19.70 (1.15)) who attended two experimental sessions: one stress and one neutral. During each session, participants completed ratings of depressive symptoms, NA, and cigarette demand.

RESULTS

We examined the predictive utility of depressive symptoms, change in NA as a result of a stressor, and the interaction between depressive symptoms and NA change on demand indices. Separate models were constructed by session. Results indicated significant interactive effects between depressive symptoms and change in NA for predicting intensity, breakpoint, and P max during the stress session. Specifically, change in NA moderated the relationship between depression and demand indices such that among individuals high in NA change, depressive symptoms were positively related to P max and breakpoint, whereas among individuals low in NA change, depressive symptoms were positively related to intensity.

CONCLUSIONS

When exposed to stress, cigarettes may become more valuable for individuals with depressive symptoms.

IMPLICATIONS

This study contributes to the literature attempting to understand the complex relationships between depression, stress-related changes in NA, and tobacco use. This study suggests that one mechanism that may be important to the relationship between depression and tobacco use is cigarette demand. Specifically, for individuals with elevated depressive symptoms, certain aspects of cigarette demand may be higher (intensity, breakpoint, and P max) when exposed to stress, which may contribute to tobacco use being maintained over time.

The substitutability of cigarettes and food: A behavioral economic comparison in normal weight and overweight or obese smokers

Obesity and cigarette smoking contribute to a multitude of preventable deaths in the United States and eating and smoking behavior may influence each other. The field of behavioral economics integrates principles from psychology and economics and permits systematic examination of how commodities interrelate with one another. Using this framework, the current study evaluated the effects of rising food and cigarette prices on consumption to investigate their substitutability and their relationship to BMI and associated variables. Behavioral economics categorizes commodities as substitutable when the consumption of one increases as a function of a price increase in the other. Smokers (N = 86) completed a 2-part hypothetical task in which money was allocated to purchase cigarettes and fast-food-style reinforcers (e.g., hamburgers, ice cream) at various prices. Results indicated that food and cigarettes were not substitutes for one another (cross-price elasticity coefficients < .20). Food purchases were independent of cigarette price, whereas cigarette purchases decreased as food price rose. Cross-price elasticity coefficients were significantly associated with confidence in one's ability to control weight without smoking (rs = -.23 and .29), but not BMI (rs = .04 and .04) or postcessation weight concerns (rs = -.05 and .12). Perceived ability to manage weight without cigarettes may influence who substitutes food for cigarettes when quitting. In addition, given observed decreases in purchases of both commodities as food prices increased, these findings imply that greater taxation of fast-food-style reinforcers could potentially reduce consumption of these foods and also cigarettes among smokers. (PsycINFO Database Record

Influence of Price and Labeling on Energy Drink Purchasing in an Experimental Convenience Store

OBJECTIVE

To examine the impact of energy drink (ED) pricing and labeling on the purchase of EDs.

METHODS

Participants visited a laboratory-based convenience store 3 times and purchased a beverage under different ED labeling (none, caffeine content, and warning labels) and pricing conditions. The 36 participants (aged 15-30 years) were classified as energy drink consumers (≥ 2 energy drinks/wk) and nonconsumers (< 1 energy drink/mo). Data were log transformed to generate elasticity coefficients. The authors analyzed changes in elasticity as a function of price and labeling using mixed-effects regression models.

RESULTS

Increasing the price of EDs reduced ED purchases and increased purchasing of other caffeinated beverages among ED consumers. Energy drink labels affected ED sales in adolescents.

CONCLUSIONS AND IMPLICATIONS

These data suggest that ED pricing and labeling may influence the purchasing of ED, especially in adolescent consumers.

A modified exponential behavioral economic demand model to better describe consumption data

Behavioral economic demand analyses that quantify the relationship between the consumption of a commodity and its price have proven useful in studying the reinforcing efficacy of many commodities, including drugs of abuse. An exponential equation proposed by Hursh and Silberberg (2008) has proven useful in quantifying the dissociable components of demand intensity and demand elasticity, but is limited as an analysis technique by the inability to correctly analyze consumption values of zero. We examined an exponentiated version of this equation that retains all the beneficial features of the original Hursh and Silberberg equation, but can accommodate consumption values of zero and improves its fit to the data. In Experiment 1, we compared the modified equation with the unmodified equation under different treatments of zero values in cigarette consumption data collected online from 272 participants. We found that the unmodified equation produces different results depending on how zeros are treated, while the exponentiated version incorporates zeros into the analysis, accounts for more variance, and is better able to estimate actual unconstrained consumption as reported by participants. In Experiment 2, we simulated 1,000 datasets with demand parameters known a priori and compared the equation fits. Results indicated that the exponentiated equation was better able to replicate the true values from which the test data were simulated. We conclude that an exponentiated version of the Hursh and Silberberg equation provides better fits to the data, is able to fit all consumption values including zero, and more accurately produces true parameter values.

The Experimental Tobacco Marketplace I: Substitutability as a Function of the Price of Conventional Cigarettes

INTRODUCTION

Behavioral economic studies of nicotine product consumption have traditionally examined substitution between two products and rarely examined substitution with more products. Increasing numbers of tobacco products available for commercial sale leads to more possible cross-product interactions, indicating a need to examine substitution in more complex arrangements that closely mirror the tobacco marketplace.

METHODS

The experimental tobacco marketplace (ETM) is an experimental online store that displays pictures, information, and prices for several tobacco products. Smokers were endowed with an account balance based on their weekly tobacco purchases. Participants then made potentially real purchases for seven (Experiment 1) or six (Experiment 2) tobacco/nicotine products under four price conditions for conventional cigarettes while prices for other products remained constant. Smokers returned 1 week later to report tobacco/nicotine use and return unused products for a refund.

RESULTS

In Experiment 1 (n = 22), cigarette purchasing decreased as a function of price. Substitution was greatest for electronic cigarettes and cigarillos and significant for electronic cigarettes. Experiment 2 (n = 34) was a replication of Experiment 1, but with cigarillos unavailable in the ETM. In Experiment 2, cigarette purchases decreased as a function of price. Substitution was robust and significant for electronic cigarettes and Camel Snus.

CONCLUSIONS

The ETM is a novel, practical assay that mimics the real-world marketplace, and functions as a simple research tool for both researchers and participants. Across the two experiments the product mix in the ETM altered which products functioned as substitutes suggesting complex interactions between purchasing and product availability.

IMPLICATIONS

This article adds a novel method of collecting purchasing data that mimics real world purchasing to the existing literature. The ETM is a practical avenue by which to study both hypothetical and potentially real purchasing.

Identification and management of nonsystematic purchase task data: Toward best practice

Experimental assessments of demand allow the examination of economic phenomena relevant to the etiology, maintenance, and treatment of addiction and other pathologies (e.g., obesity). Although such assessments have historically been resource intensive, development and use of purchase tasks-in which participants purchase 1 or more hypothetical or real commodities across a range of prices-have made data collection more practical and have increased the rate of scientific discovery. However, extraneous sources of variability occasionally produce nonsystematic demand data, in which price exerts either no or inconsistent effects on the purchases of individual participants. Such data increase measurement error, can often not be interpreted in light of research aims, and likely obscure effects of the variable(s) under investigation. Using data from 494 participants, we introduce and evaluate an algorithm (derived from prior methods) for identifying nonsystematic demand data, wherein individual participants' demand functions are judged against 2 general, empirically based assumptions: (a) global, price-dependent reduction in consumption and (b) consistency in purchasing across prices. We also introduce guidelines for handling nonsystematic data, noting some conditions in which excluding such data from primary analyses may be appropriate and others in which doing so may bias conclusions. Adoption of the methods presented here may serve to unify the research literature and facilitate discovery.

Behavioral Economics of Cigarette Purchase Tasks: Within-Subject Comparison of Real, Potentially Real, and Hypothetical Cigarettes

INTRODUCTION

Hypothetical rewards are commonly used in studies of laboratory-based tobacco demand. However, behavioral economic demand procedures require confirmation that the behavior elicited from real and hypothetical reward types are equivalent, and that results attained from these procedures are comparable to other accepted tasks, such as the hypothetical purchase task.

METHODS

Nineteen smokers were asked to purchase 1 week's worth of cigarettes that they would consume over the following week either at one price that incrementally increased across four weekly sessions ("real" sessions) or four prices in a single session ("potentially real" session), one of which was randomly chosen to be actualized. At each session, participants also completed a hypothetical cigarette purchase task. After each week, participants reported the number of cigarettes they actually smoked.

RESULTS

Demand was found to be equivalent under both the real and potentially real reward conditions but statistically different from the demand captured in the hypothetical purchase task. However, the amounts purchased at specific prices in the hypothetical purchase task were significantly correlated with the amount purchased at comparable prices in the other two tasks (except for the highest price examined in both tasks of $1.00 per cigarette). Number of cigarettes consumed that were obtained outside of the study was correlated with study cigarette price.

CONCLUSIONS

Combined, these results suggest that purchasing behavior during potentially real sessions (1) was not functionally different from real sessions, (2) imposes fewer costs to the experimenter, and (3) has high levels of both internal and external validity.