Chapter

Intertemporal Choice

January 2008

DOI:10.1057/978-1-349-95121-5_1987-1

In book: The New Palgrave Dictionary of Economics (pp.1-8)

Authors:

Harvard University

Decisions that have consequences in multiple time periods are intertemporal choices. Individuals typically discount delayed rewards much more than can be explained by mortality effects. The most common discount function is exponential in form, but hyperbolic and quasi-hyperbolic functions seem to explain empirical data better. Individual discount rates may be measured in a variety of ways, subject to important methodological caveats. Higher discount rates are empirically associated with a variety of substance abuse and impulsive conditions, including smoking, alcoholism, cocaine and heroin use, gambling, and risky health behaviours. By contrast, low discount rates may be associated with high cognitive ability.

Improving Teacher Effectiveness in Schools in Delhi through Behaviorally Informed Lesson Planning Intervention

Conference Paper

Full-text available

Mar 2018

In this paper we propose a behaviorally informed intervention to address the 'learning crisis' plaguing government schools in Indian. The proposed intervention is aimed at encouraging government school teachers to create and employ lesson plans to increase their effectiveness and improve student learning outcomes. We use behaviorally informed tools such as enhanced active choice, defaults, anchors, and checklists. As well as behavioral insights on social norms and present-bias to inform our intervention design.

Is Information in the Brain Represented in Continuous or Discrete Form?

Preprint

May 2018

The question of continuous-versus-discrete information representation in the brain is a fundamental yet unresolved physiological question. Historically, most analyses assume a continuous representation without considering the alternative possibility of a discrete representation. Our work explores the plausibility of both representations, and answers the question from a communications engineering perspective. Drawing on the well-established Shannon's communications theory, we posit that information in the brain is represented in a discrete form. Using a computer simulation, we show that information cannot be communicated reliably between neurons using a continuous representation, due to the presence of noise; neural information has to be in a discrete form. In addition, we designed 3 (human) behavioral experiments on probability estimation and analyzed the data using a novel discrete (quantized) model of probability. Under a discrete model of probability, two distinct probabilities (say, 0.57 and 0.58) are treated indifferently. We found that data from all participants were better fit to discrete models than continuous ones. Furthermore, we re-analyzed the data from a published (human) behavioral study on intertemporal choice using a novel discrete (quantized) model of intertemporal choice. Under such a model, two distinct time delays (say, 16 days and 17 days) are treated indifferently. We found corroborating results, showing that data from all participants were better fit to discrete models than continuous ones. In summary, all results reported here support our discrete hypothesis of information representation in the brain, which signifies a major demarcation from the current understanding of the brain's physiology.

Towards a Utility Theory of Privacy and Information Sharing and the Introduction of Hyper-Hyperbolic Discounting in the Digital Big Data Age

Article

Full-text available

Jan 2017

Julia M. Puaschunder

A Influência das Variáveis Sociodemográficas Renda, Gênero e Idade nas Preferências Temporais

Article

Full-text available

Aug 2021

Objetivo: O presente estudo tem por objetivo analisar o comportamento das preferências temporais, utilizando-se como parâmetros as características sociodemográficas renda, gênero e idade. Fundamento: À luz das finanças comportamentais, o estudo fundamenta-se na teoria da racionalidade limitada de Simon (1957) para análise das preferências intertemporais, as quais apresentam-se como fatores heterogêneos que se modificam de acordo com arranjos sociais e psicológicos. Método: Empreendeu-se uma pesquisa de natureza quantitativa, cuja consecução foi obtida através da aplicação de um survey, na qual participaram 133 estudantes de ensino superior. Para análise dos dados foram utilizados módulos de estatística descritiva, teste t de Student e análise de variância (ANOVA). Resultados: Os participantes apresentaram um padrão de preferência hiperbólica, indicando uma maior valorização pelo consumo imediato do que uma gratificação futura. Ademais, as preferências temporais são influenciadas por aspectos pecuniários, indicando que quanto maior a renda, maior o nível de paciência dos indivíduos. Por outro lado, embora os mais jovens tenham apresentado maiores níveis de impaciência, a associação da variável idade com as preferências temporais foram apenas marginalmente significantes. Quanto ao gênero, ao contrário das acepções teóricas levantadas na literatura, observa-se que mulheres apresentam menor nível de paciência do que os homens. Contribuições: Este estudo contribui para a expansão teórico-prática da discussão das preferências intertemporais. Buscando compreender este fenômeno de uma maneira mais realista, os resultados revelam contra-argumentos aos princípios postulados pela economia clássica. Ademais, a heterogeneidade das preferências temporais revela como os múltiplos condicionantes socioeconômicos e psicológicos podem afetar as tomadas de decisões econômicas. Palavras-chave: Preferências Temporais. Finanças Comportamentais. Desconto Exponencial. Desconto Hiperbólico.

Heterodox Economic Cycles Theories

Article

Full-text available

Jan 2021

Julia M. Puaschunder

Overall the following article innovatively paints a novel picture of the mass psychological underpinnings of business cycles based on information flows in order to recommend how certain communication strategies could counterweight and alleviate the building of disastrous financial market mass movements. Acknowledging that human beings are connected to and interact with each other in families, ties and larger networks of states, nations and intergovernmental institutions, studying the role of information in building socially-constructed economic correlates promises to explain how market outcomes are developed in the social compound and can be guided by media communication. Addressing problems of the neoclassical assumption of perfect information markets through the lens of ‘real competition,’ the following paper will specifically unravel how contemporary media communication produces certain types of price expectations that form consumption patterns leading to collectively-shared economic outcomes. An introduction to the history of economic cycles will lead to the analysis of the role of information in creating economic booms and busts in the age of globalization. Applying emergent risk theory onto economic fluctuations will serve as an innovative way to explain how and what information represented in the media creates economic ups and downs. Linguistic roots of news about the economy are aimed at shedding light on how media representations and temporal foci echo in economic correlates and shape market outcomes. As business cycles are a collective phenomenon, group interactions’ potential contribution to create business cycles will innovatively be outlined and the role of information flows among groups in creating price expectations unraveled. Business cycles will also be shown to obey some kind of natural complexity, as for being whimsically influenced by socio-historic and political trends. Recommendations how to create more stable economic systems by avoiding emergent risks and communicating market prospects more cautiously will be given in the discussion followed by a prospective future research outlook and conclusion.

Financial Behavioralism: A Behavioral Finance Approach to Minimize Losses and Maximize Profits from Heuristics and Biases

Chapter

Full-text available

Oct 2020

Julia M. Puaschunder

In an impressive line of experiments and field studies, the growing field of behavioral finance has offered behavioral insights on how markets deviate from rationality. Human actors are prone to base their investment choices on very many other factors than simply volatility and profit maximization opportunities. Most recently nudging has started using the emerging insights about human heuristics and biases to improve decision making in different domains ranging from health, wealth and prosperity, which are covered in the following chapters. The following part reviews some of the behavior insights gained in the last decades and shows ways how to profit from heuristics and biases.

Nudgitize me! A behavioral Finance Approach to minimize losses and maximize profits from Heuristics and Biases

Article

Full-text available

Feb 2018

Julia M. Puaschunder

Behavioral Finance is one of the most novel developments in Behavioral Economics. Since the end of the 1970ies a wide range of psychological, economic and sociological laboratory and field experiments proved human beings deviating from rational choices. Standard neoclassical profit maximization axioms were outlined to fail to explain how human actually behave. Human beings were rather found to use heuristics in the day-to-day decision making. These mental short cuts enable to cope with information overload in a complex world. Behavioral economists proposed to nudge and wink citizens to make better choices for themwith many different applications in very many different domains. This paper reviews and proposes how to use mental heuristics, biases and nudges in the finance domain to profit from markets.

A Quantized Representation of Intertemporal Choice in the Brain

Preprint

Full-text available

Sep 2020

Value [4][5] is typically modeled using a continuous representation (i.e., a Real number). A discrete representation of value has recently been postulated [6]. A quantized representation of probability in the brain was also posited and supported by experimental data [7]. In this paper, we hypothesize that intertemporal choices may also be quantized. For example, people may treat (or discount) 16 days indifferently to 17 days. To test this, we analyzed an intertemporal task by using 2 novel models: quantized hyperbolic discounting, and quantized exponential discounting. Our work here is a re-examination of the behavioral data previously collected for an fMRI study [8]. Both quantized hyperbolic and quantized exponential models were compared using AIC and BIC tests. We found that 13/20 participants were best fit to the quantized exponential model, while the remaining 7/20 were best fit to the quantized hyperbolic model. Overall, 15/20 participants were best fit to models with a 5-bit precision (i.e., 2^5 = 32 steps). Our key conclusion is that, regardless of whether a hyperbolic or an exponential model is employed, quantized versions are a better fit to the experimental data than their continuous versions. We finally outline some potential applications of our findings.

Learning Time Dependent Choice

Preprint

Full-text available

Sep 2018

We explore questions dealing with the learnability of models of choice over time. We present a large class of preference models defined by a structural criterion for which we are able to obtain an exponential improvement over previously known learning bounds for more general preference models. This in particular implies that the three most important discounted utility models of intertemporal choice -- exponential, hyperbolic, and quasi-hyperbolic discounting -- are learnable in the PAC setting with VC dimension that grows logarithmically in the number of time periods. We also examine these models in the framework of active learning. We find that the commonly studied stream-based setting is in general difficult to analyze for preference models, but we provide a redeeming situation in which the learner can indeed improve upon the guarantees provided by PAC learning. In contrast to the stream-based setting, we show that if the learner is given full power over the data he learns from -- in the form of learning via membership queries -- even very naive algorithms significantly outperform the guarantees provided by higher level active learning algorithms.

The Impact of Financial Education on Adolescents’ Intertemporal Choices

Article

Aug 2018

We study the impact of financial education on intertemporal choice in adolescence. The educational program was randomly assigned among high school students, and choices were measured using an incentivized experiment. Students who participated in the program make more time-consistent choices; are more likely to allocate payments to a single payment date, as opposed to spreading payment across two dates; and display increased consistency of choice with the law of demand. These findings suggest that financial education increases the quality of intertemporal decision-making and decreases narrow bracketing.

Decision Choice under Pareto Optimal Criteria

Article

Full-text available

Aug 2022

Sidharta Chatterjee

According to the axiomatic foundations of social choice theory, not all decisions benefit everyone. Often, decisions that do not have any implied benefit for the decision maker are made in the (best) interests of others. When a decision is made concerning welfare of others, some individuals—including the decision maker, may be on the receiving end. For, it is impossible to make social decisions by taking into account individual preferences that satisfy all and everyone. This is on account of a great variety in individual choices and preferences ubiquitous among different individuals. Tastes vary among different people—so does individual preferences, and that’s natural. Conflict of interests arises due to subtle variances in individual preferences. In this paper, we discuss about the decision choice that seldom works for every conceivable set of individual preferences. Following Arrovian precepts, it is impossible to satisfy one and all, for there remains a great diversity in individual preferences that result in the problem of choice. Hence, in this research, we develop a taste-based theory of social choice that attempts to address the problem of choice by helping individuals choose the best and the most effective and optimal option among a given set of alternatives that’s assumed to be rational.

Behavioural Insights, Organisational Resilience, and Disaster Preparedness

Chapter

Jul 2022

Massive and unpredictable business disruptions caused by waves of conflict, crises, and disasters reinforce the need for businesses to take on a proactive approach to disaster preparedness. Failure to do so will result in a loss of market share and customer goodwill, damaged reputation, and regulatory and legal liabilities. Considering that high-stake and difficult business decision-making often relies on mental shortcuts or heuristics, behavioural approaches to enable businesses to prepare for disasters are required. Behavioural Insights’ use of behavioural science to explain and alter patterns of behaviour can be an important tool in business disaster preparedness. In the business context, the use of Behavioural Insights has been found to increase employment rate, retirement savings, emergency agency response effectiveness, workplace flow, and acts of prosociality. In this chapter, we focus on how BI can help businesses build greater organisational resilience through interventions and nudges before, during, and after a disaster. We conclude by calling for the need to consider the types of business (e.g., SMEs versus MNCs) when planning BI interventions for disaster preparedness.

TO BUY OR NOT TO BUY CRYPTO - COGNITIVE REFLECTION, TEMPORAL DISCOUNTING, AND RISK PREFERENCE IN CRYPTO ASSETS ADOPTION

Conference Paper

Full-text available

May 2022

Nikola Levkov

The purpose of this research in progress is to investigate the potential impact of Cognitive Reflection Test (CRT) scores, temporal discounting, and risk preferences on crypto-assets adoption and non-adoption. This article, therefore, proposes a novel theoretical framework and hypotheses which can potentially improve the understanding of the financial behavior of crypto-assets adopters and non-adopters. Integrating the existing body of knowledge from Dual Process Theory, Theory of Discounted Utility and Prospect Theory enables us to use cognitive reflection scores, discount rates, and risk preferences as constituents of crypto-assets adopters and non-adopters. The intention of this research proposal is to test the soundness of our theoretical framework and hypothesеs and to enhance our theoretical framework and hypotheses, as well as overall paper, based on the conference feedback and our initial findings in the near future.

A behavioral approach to voluntary change and innovation in external financial reporting: A case study of the restructuring of the Annual Report on Form 20-F and the Financial Report

Conference Paper

Full-text available

Dec 2020

A behavioral approach to voluntary change and innovation in external financial reporting: A case study of the restructuring of the Annual Report on Form 20-F and the Financial Report

Article

Full-text available

Jan 2020

The role of time estimation in decreased impatience in Intertemporal Choice

Preprint

Full-text available

Dec 2020

The role of specific cognitive processes in deviations from constant discounting in intertemporal choice is not well understood. We evaluated decreased impatience in intertemporal choice tasks independent of discounting rate and non-linearity in long-scale time representation; nonlinear time representation was expected to explain inconsistencies in discounting rate. Participants performed temporal magnitude estimation and intertemporal choice tasks. Psychophysical functions for time intervals were estimated by fitting linear and power functions, while discounting functions were estimated by fitting exponential and hyperbolic functions. The temporal magnitude estimates of 65% of the participants were better fit with power functions (mostly compression). 63% of the participants had intertemporal choice patterns corresponding best to hyperbolic functions. Even when the perceptual bias in the temporal magnitude estimations was compensated in the discounting rate computation, the data of 8 out of 14 participants continued exhibiting temporal inconsistency. The results suggest that temporal inconsistency in discounting rate can be explained to different degrees by the bias in temporal representations. Non-linearity in temporal representation and discounting rate should be evaluated on an individual basis. Keywords: Intertemporal choice, temporal magnitude, model comparison, impatience, time inconsistency

Behavioral Economics

Chapter

Full-text available

Oct 2020

Julia M. Puaschunder

Since the end of the 1970s, a wide range of psychological, economic, and sociological laboratory and field experiments proved human beings deviating from rational choices. Standard neoclassical profit maximization axioms were outlined to fail to explain how humans actually behave. Human beings were rather found to use heuristics in day-to-day decision-making. These mental shortcuts enable us to cope with information overload in a complex world. Behavioral economists proposed to nudge and wink citizens to make better choices with many different applications in very many different domains. This book will (1) start with a review of the contemporary literature on human decision-making failures in Europe and North America presenting the wide range of nudges and winks developed to curb harmful consequences of humane decision-making fallibility; then (2) propose how to use mental heuristics, biases, and nudges in the finance domain to profit from economic markets providing clear communication strategies; and then (3) finish with clear leadership and followership directives on nudging in the digital age.

What Are the Headwaters of Formal Savings? Experimental Evidence from Sri Lanka

Article

Full-text available

Nov 2019

The world’s poor are seeing a rapid expansion in access to formal savings accounts. What is the source of savings when households are connected to a formal account? We combine a high-frequency panel survey spanning two and a half years with an experiment in which a Sri Lankan bank used mobile Point-of-Service (POS) terminals to collect deposits directly from households each week. We find that the headwaters of formal savings lie in sacrificed leisure time: households work more, and improved savings options generate an increase in labour effort in both self-employment and in the wage market. The results suggest that the labour allocation channel is an important mechanism linking savings opportunities to income.

Procrastination in the Field: Evidence from Tax Filing

Article

Jan 2017

This paper attempts to identify present-biased procrastination in tax filing behavior. Our exercise uses dynamic discrete choice techniques to develop a counterfactual benchmark for filing behavior under the assumption of exponential discounting. Deviations between this counterfactual benchmark and actual behavior provide potential ‘missing-mass' evidence of present bias. In a sample of around 22,000 low-income tax filers we demonstrate substantial deviations between exponentially-predicted and realized behavior, particularly as the tax deadline approaches. Present-biased preferences not only provide qualitatively better in-sample fit than exponential discounting, but also have improved out-of-sample predictive power for responsiveness of filing times to the 2008 Economic Stimulus Act recovery payments. Additional experimental data from around 1100 individuals demonstrates a link between experimentally measured present bias and deviations from exponential discounting in tax filing behavior.

Dignity of Privacy or Utility in Communication? The Predicament of Digitalization in the Big Data Age

Article

Full-text available

Jan 2020

Julia M. Puaschunder

Time Preferences over the Life Cycle

Article

Jan 2020

Data Fiduciary in Order to Alleviate Principal-Agent Problems in the Artificial Big Data Age

Article

Full-text available

Jan 2019

Julia M. Puaschunder

ESSAYS ON DECISION MAKING

Preprint

Full-text available

Mar 2016

Guangpu Yang

Focusing on people's attitudes towards time, Chapter 1 explored the genetic root for the variations in time discounting and the near-term bias across individuals, and found that the expression level of the retinoic acid receptor-a (RARA) gene in peripheral blood is positively correlated with the degree of impatience in the remote future but negatively correlated with the degree of near-term bias. In Chapter 2, we elicited people?s attitudes towards uncertainty based on four decision tasks involving different types of uncertainty, selected 10 candidate genes, and found that people? attitudes towards different types of uncertainty are associated with the expression level of different genes. In Chapter 3, we focus on the interaction of people's attitudes towards uncertainty and time, and propose three main hypotheses based on a thorough review of the conceptual background. These hypotheses are tested based on a large-sample experiment.

A Theoretical Framework for Teacher Incentives: Monetary, Social and Vision-Based

Research

Full-text available

Oct 2018

Farah Mallah

Teachers are at the heart of the education process; in attempts to improve teacher quality there has been a trend in the US and elsewhere to incentivize teachers to put in more effort. This paper presents a theoretical framework for analyzing and designing different incentive schemes informed by the structure and quality of tasks constituting the k-12 teaching profession. It focuses on the question of how policy makers and education leaders can improve teacher effort towards the outcome of interest, specifically improving student achievement. It draws on literature on incentives, goal setting theory, norms and work significance to identify three main types of incentives: (1) monetary incentives, (2) social incentives and (3) vision-based incentive. Each of the types of incentives in this paper are analyzed in light of Vroom’s (1964) expectancy theory – its expectancy, valence and instrumentality – to build a theoretical framework for analyzing the potential mediating factors of each of the incentive schemes and their impact.

Self-Control in Intertemporal Choice and Mediterranean Dietary Pattern

Article

Full-text available

Jun 2018

Background: The Mediterranean Diet (hereinafter MD) is considered a healthy dietary pattern. Adherence to this pattern can be assessed by means of the KIDMED test by which individuals are assigned an index and classified into three groups of adherence to MD: high, medium, and low. In addition, impulsivity or impatience in intertemporal choice has been defined as a strong preference for small immediate rewards over large delayed ones. Objective: This study examines the relationship between dietary habits, specifically Mediterranean dietary pattern, measured by the KIDMED index, and the exhibited impatience in intertemporal choices, by means of the parameter k (discount rate of the hyperbolic discount function). Methods: A sample of 207 university students answered a questionnaire based on two tests: the KIDMED test, to assess the degree of adherence to MD, and an intertemporal choice questionnaire, to assess impatience or impulsivity. Individuals were grouped depending on their KIDMED score and then the discount rate or impulsivity parameter was calculated for each group. Results: Discount rates were inversely related to the degree of adherence to MD. The values of overall k were 1.53, 1.91, and 3.71% for the groups exhibiting high, medium and low adherence to MD, respectively. We also found higher k-values for larger rewards (magnitude effect) in the three groups. Conclusion: High adherence to MD is related to less steep time discounting, which implies less impulsivity (more self-control) or lower discount rates. Conversely, low adherence to MD is related to steeper time discounting, which implies impulsivity or higher discount rates. These findings could be used to identify the target population where policy interventions are needed in order to promote healthier diet habits.

An Extended Survey on Time-Inconsistency and Its Applications

Article

Jan 2018

Murat Yilmaz

In this study, we provide an extended literature review on preferences with present bias, more specifically with quasi-hyperbolic discounting which leads to time-inconsistent behavior. We review current studies that focus on the implications of time-inconsistent preferences on various well-known economic models and environments, including both models of individual decision making and models that have strategic interactions. We also discuss the part of the literature that focuses on measuring the discounting, whether it is exponential or hyperbolic. We also provide possible research directions which have not been fully explored yet in the literature.

Overcoming behavioral obstacles to escaping poverty

Article

Full-text available

Jan 2017

Behaviorally informed policies for household financial decisionmaking

Article

Full-text available

Jan 2017

Dynamic Inconsistency in Food Choice: Experimental Evidence from a Food Desert

Article

Jan 2015

Despite the great deal of research on dynamic inconsistency in time preferences, few studies have ventured into investigating the question in a natural context. To address this gap, we conduct a natural field experiment with over 200 customers at a grocery store to investigate dynamic inconsistency and the demand for commitment in food choice. Over a 3 week time period, subjects are invited to allocate and re-allocate food items received as part of a grocery delivery program. We observe substantial dynamic inconsistency in our experiment, as well as a demand for commitment among a non-negligible number of subjects. Interestingly, individuals who demand commitment are more likely to be dynamically consistent in their prior behavior. For academics, our work provides direct evidence of dynamic inconsistency in consumption choices in the field and points towards potential extensions to models of temptation. For policy-makers, our findings provide insights on innovations to alter food choices.

On the persistence of dishonesty

Article

Aug 2022
J ECON BEHAV ORGAN

In social and economic interactions, individuals often exploit informational asymmetries and behave dishonestly to pursue private ends. In many of these situations, the costs and benefits from dishonest behavior do not accrue immediately and at the same time. In this paper, we experimentally investigate the role of time on dishonesty. Contrary to our predictions, we find that neither delaying the gains from cheating nor increasing temporal engagement with one’s own unethical behavior reduces the likelihood of cheating. Furthermore, providing individuals with an excuse to lie by inserting a delay between the time when private information is obtained and when it is reported does not affect cheating.

Learning About One’s Self

Article

Mar 2022

To understand why naiveté about present-biased behavior is so prevalent and persistent, our experiment investigates how well participants learn from their past behavior in a real-effort task. While participants display naive present-biased behavior initially, our novel methodology allows us to establish that their updating is unbiased and would eliminate naiveté in the long run. Moreover, learning is unencumbered by a change in environment. Our results suggest that persistent naiveté does not result from a fundamental inferential bias. However, participants underestimate their future learning—a bias that may lead to underinvestment in experimentation and a failure to activate self-regulation mechanisms.

A guaranteed immediate payout reduces impatience of financially constrained individuals

Article

Full-text available

Jan 2022

Significance A wealth of existing findings show that financially constrained individuals are myopic decision-makers who are particularly concerned about the present. We propose that the use of existing intertemporal choice tasks may have skewed our understanding of the decision-making of financially constrained individuals. Specifically, we observe that—as long as an immediate payout is guaranteed—financially constrained individuals are no more myopic than their more affluent counterparts.

"I Feel Therefore I Decide": Effect of Negative Emotions on Temporal Discounting and Probability Discounting

Article

Full-text available

Oct 2021
BSRCCS

Citation: Calluso, C.; Devetag, M.G.; Donato, C. "I Feel Therefore I Decide": Effect of Negative Emotions on Temporal Discounting and Probability Discounting. Brain Sci. Abstract: Temporal and probability discounting are considered two fundamental constructs in economic science, as they are associated with phenomena with major societal impact and a variety of sub-optimal behaviors and clinical conditions. Although it is well known that positive and negative affective states bear important cognitive/behavioral consequences, the effect of emotional experiences on decision-making remains unclear due to the existence of many conflicting results. Inspired by the need to understand if and to what extent the current COVID-19 pandemic has determined changes in our decision-making processes by means of the unusual, prolonged experience of negative feelings, in this study we investigate the effect of anger, fear, sadness, physical and moral disgust on intertemporal and risky choices. Results show that all emotions significantly increase subjects' preferences for immediate rewards over delayed ones, and for risky rewards over certain ones, in comparison to a "neutral emotion" condition, although the magnitude of the effect differs across emotions. In particular, we observed a more pronounced effect in the case of sadness and moral disgust. These findings contribute to the literature on emotions and decision-making by offering an alternative explanation to the traditional motivational appraisal theories. Specifically, we propose that the increased preference for immediate gratification and risky outcomes serves as a mechanism of self-reward aimed at down-regulating negative feelings and restore the individual's "emotional balance".

Time Preferences over the Life Cycle and Household Saving Puzzles

Article

Oct 2021
J MONETARY ECON

Most economic models assume that time preferences are stable over time, but the evidence on their long-term stability is lacking. We study whether and how time preferences change over the life cycle, using representative long-term panel data. We provide new evidence that discount rates decrease with age and the decline is remarkably linear over the life cycle. Decreasing discount rates help a canonical life-cycle model explain the saving puzzles of households undersaving when young and oversaving after retirement. Relative to the model with constant discounting, the model’s fit to consumption and asset data profiles improves by 40% and 30%, respectively.

Intra-individual stability of two survey measures on forward-looking attitude

Article

Oct 2021
J ECON BEHAV ORGAN

Malte Preuss

Using representative panel data sets from the Netherlands and Germany, this study analyzes the long-term stability of two behaviorally validated measures on individuals’ forward-looking attitude: the consideration of future consequences scale and two ultra-short survey items on patience and impulsiveness. Overall, their intra-individual correlation is sufficiently high to consider the measures as stable, and a comprehensive list of live events does not correlate with their instability. Past events have only a small and time-restricted effect, if any. Robustness tests indicate that measurement errors seem to be the most likely reason for their instability. Although these findings mitigate endogeneity concerns, error-in-variable biases can, nevertheless, be substantial.

The relationship between delay discounting and Internet addiction: A systematic review and meta-analysis

Article

Mar 2021
ADDICT BEHAV

Aims To estimate the difference in delay discounting (DD) between subjects with Internet addiction (IA) and those without as well as to identify significant variables involved in DD. Methods Using the keywords related to IA (e.g., “excessive Internet use”, “Internet dependence”) AND “delayed reward discounting” OR “delay discounting” OR “temporal discounting” OR “delayed gratification” OR time discounting OR intertemporal choice OR impulsive choice, the PubMed, Embase, and PsycINFO databases were searched from inception to June 2020 for English articles with comparison between subjects with IA and those without. Effect sizes were calculated by group means from the k value or area under the curve (AUC). The random-effects models were used. Results Fourteen studies in total were eligible for the current meta-analysis that involved 696 subjects with IA (mean age = 22.71) and 2,394 subjects without (mean age = 21.91). Subjects with IA had a steeper DD rate (g = 1.10, 95% CI: 0.57–1.64; p ≤ 0.01) compared with that in those without. Regarding DD data, the difference between k value and AUC was significant (p < 0.01; AUC > k). Additionally, the estimation of DD by the paper-and-pencil task was larger than that by the computerized task (p < 0.01). Significant difference in the DD rate was also noted between subjects with Internet gaming disorder (IGD) and those with unspecified IA (p = 0.00; IGD > IA). The percentage of men and task variables were significantly associated with the DD rate (all p < 0.01), suggesting impaired DD in subjects with IA. Conclusions Our results suggested the feasibility of utilizing the DD rate as a therapeutic index for cognitive control in IA. Nevertheless, judicious use is recommended taking into consideration the significant difference between k value and AUC.

Identifying Present-Bias from the Timing of Choices

Article

Jan 2019

Dynamic Inconsistency in Food Choice: Experimental Evidence from Two Food Deserts

Article

Jul 2020

We conduct field experiments to investigate dynamic inconsistency and commitment demand in food choice. In two home grocery delivery programs, we document substantial dynamic inconsistency between advance and immediate choices. When given the option to commit to their advance choices, around half of subjects take it up. Commitment demand is negatively correlated with dynamic inconsistency, suggesting those with larger self-control problems are less likely to be aware thereof. We evaluate the welfare consequences of dynamic inconsistency and commitment policies with utility measures based on advance, immediate, and unambiguous choices. Simply offering commitment has limited welfare (and behavioural) consequences under all measures.

A Quantized Representation of Intertemporal Choice in the Brain

Article

Sep 2020

Value 45 is typically modeled using a continuous representation (i.e., a Real number). A discrete representation of value has recently been postulated 6. A quantized representation of probability in the brain was also posited and supported by experimental data 7. Value and probability are inter-related via Prospect Theory 45. In this paper, we hypothesize that intertemporal choices may also be quantized. For example, people may treat (or discount) 16 days indifferently to 17 days. To test this, we analyzed an intertemporal task by using 2 novel models: quantized hyperbolic discounting, and quantized exponential discounting. Our work here is a re-examination of the behavioral data previously collected for an fMRI study 8. Both quantized hyperbolic and quantized exponential models were compared using AIC and BIC tests. We found that 13/20 participants were best fit to the quantized exponential model, while the remaining 7/20 were best fit to the quantized hyperbolic model. Overall, 15/20 participants were best fit to models with a 5-bit precision (i.e., 25 = 32 steps). In conclusion, regardless of hyperbolic or exponential, quantized versions of these models are better fit to the experimental data than their continuous forms. We finally outline some potential applications of our findings.

Intertemporal Choice Experiments and Large-Stakes Behavior

Article

Full-text available

Sep 2020
J ECON BEHAV ORGAN

Intertemporal choice experiments are increasingly implemented to make inference about discounting and marginal utility, yet little is known about the predictive power of resulting measures. This project links standard experimental choices to a decision on the desire to smooth a large-stakes payment | around 10% of annual income | through time. In a sample of around 400 Guatemalan Conditional Cash Transfer recipients, we find that preferences over large-stakes payment plans are closely predicted by experimental measures of patience and diminishing marginal utility. These represent the first findings in the literature on the predictive content of such experimentally elicited measures of discounting and marginal utility for a large-stakes decision.

Using Preference Estimates to Customize Incentives: An Application to Polio Vaccination Drives in Pakistan

Article

Feb 2016

We use structural estimates of time preferences to customize incentives for polio vaccinators in Lahore, Pakistan. We measure time preferences using intertemporal allocations of effort, and derive the mapping between these structural estimates and individually optimized incentives. We evaluate the effect of matching contract terms to discounting parameters in a subsequent experiment with the same vaccinators. This exercise provides a test of the specific point predictions given by structural estimates of discounting parameters. We demonstrate that tailoring contract terms to individual discounting moves allocation behavior significantly towards the intended objective.

Enhancing intuition in problem solving through problem finding

Chapter

Jul 2020

Identifying present bias and time preferences with an application to land-lease-contract data*

Article

Jun 2020

What can contracts –traded and priced in a competitive market and featuring a pre-specified system of future payments– teach us about time preferences and present bias? We first show that identification of present bias requires assumptions on the felicity function and that agents must have credit constraints on consumption expenditure. Moreover, when there is heterogeneity in present bias, identification requires that agents with the same present bias parameter buy houses with different contracts. We illustrate our findings with observational land-lease contract data from Amsterdam.

Personal Impulsivity Mediates the Effects of Neuromodulation in Economic Intertemporal Choices: A Pilot Study

Article

Full-text available

Jun 2020
STUD PSYCHOL

The involvement of the prefrontal cortex in intertemporal choices has been long recognized. Using neurostimulation techniques, recent studies have indicated that the left dorsolateral prefrontal cortex (DLPFC) influences performance on intertemporal choice tasks. The present pilot study is aimed to explore further the DLPFC's role in intertemporal choices by assessing the influence of individual levels of impulsivity on modulating the stimulation's effects. Thirteen subjects participated in a within-subjects experiment. During the three sessions, participants received 20 minutes of transcranial direct current stimulation (tDCS; either sham, anodal, or cathodal) and were administered the Intertemporal Choice Task. Then, they completed the Barratt Impulsivity Scale and the Dickman Impulsivity Inventory. Using a repeated measure generalized linear model, we explored the effects of stimulation on intertemporal choice (either immediate or delayed reward) on impulsive responses, defined as quick answers. The individual level of impulsivity was included in the model as a covariate. According to the results, participants made a greater number of impulsive choices favoring immediate rewards after cathodal stimulation of the left DLPFC. Additionally, a moderating role of individual impulsivity emerged. This study provides support for the involvement of the left DLPFC in intertemporal choices. We contend that the role of individual differences should be further explored to obtain a better understanding of intertemporal choice behavior.

Meta-Analysis of Present-Bias Estimation Using Convex Time Budgets

Article

Full-text available

Jul 2019

We examine 220 estimates of the present-bias parameter from 28 articles using the Convex Time Budget protocol. The literature shows that people are on average present biased, but the estimates exhibit substantial heterogeneity across studies. There is evidence of modest selective reporting in the direction of overreporting present-bias. The primary source of the heterogeneity is the type of reward, either monetary or non-monetary reward, but the effect is weakened after correcting for potential selective reporting. In the studies using the monetary reward, the delay until the issue of the reward associated with the “current” time period is shown to influence the estimates of present bias parameter.

A Quantized Representation of Probability in the Brain

Article

Full-text available

Oct 2019

Conventional and current wisdom assumes that the brain represents probability as a continuous number to many decimal places. This assumption seems implausible given finite and scarce resources in the brain. Quantization is an information encoding process whereby a continuous quantity is systematically divided into a finite number of possible categories. Rounding is a simple example of quantization. We apply this information theoretic concept to develop a novel quantized (i.e., discrete) probability distortion function. We develop three conjunction probability gambling tasks to look for evidence of quantized probability representations in the brain. We hypothesize that certain ranges of probability will be lumped together in the same indifferent category if a quantized representation exists. For example, two distinct probabilities such as 0.57 and 0.585 may be treated indifferently. Our extensive data analysis has found strong evidence to support such a quantized representation: 59/76 participants (i.e., 78%) demonstrated a best fit to 4-bit quantized models instead of continuous models. This observation is the major development and novelty of the present work. The brain is very likely to be employing a quantized representation of probability. This discovery demonstrates a major precision limitation of the brain’s representational and decision-making ability.

Does marriage work as a savings commitment device? Experimental evidence from Vietnam

Article

Full-text available

Jun 2019
PLOS ONE

Present bias, or the overvaluation of an immediate payoff, causes under-saving and financial difficulty. We investigate whether married couples utilize their spouses as a savings commitment device to alleviate the present bias problem using experimental and survey data in Vietnam. We find that individuals are less present biased when making joint decisions with their spouses than they are when making decisions alone. However, present-biased individuals turn over a smaller ratio of their earnings to their spouses and are more likely to manage household resources than time-consistent individuals are. Present-biased individuals also receive larger amounts of money from their spouses’ incomes, indicating that marriage not only fails to function as a savings commitment device but also exacerbates the problem. Married couples whose joint decisions are not present biased try to alleviate this problem by allocating smaller allowances to present-biased spouses, but the present-biased spouses conceal money to counteract this strategy. Our study indicates the importance of external savings commitment devices in helping people protect money from their present-biased spouses.

Subjective Wellbeing and the Discount Rate

Article

Full-text available

Feb 2020

James Kennedy

Academic and policy interest in the determinants of subjective well-being continues to grow. To date, the role of temporal discounting—the extent to which people devalue future rewards—in people’s reports of their subjective well-being has remained unexplored. This paper is the first to provide evidence on the relationship between discount rates and evaluative and hedonic subjective well-being. Using data from a nationally representative sample of 2000 UK respondents in multiple regression analyses, the results suggest that people who devalue future rewards are less satisfied with life and less happy than those who place greater value on future outcomes. However, those who discount heavily are also more likely to expect that they will be happier in the future.

DAVRANIŞSAL İKTİSAT VE ZAMANLARARASI TERCİH: TASARRUF DAVRANIŞI ÜZERİNE BİR İNCELEME

Article

Dec 2018

Intertemporal Choice of Fuzzy Soft Sets

Article

Full-text available

Sep 2018

This paper first merges two noteworthy aspects of choice. On the one hand, soft sets and fuzzy soft sets are popular models that have been largely applied to decision making problems, such as real estate valuation, medical diagnosis (glaucoma, prostate cancer, etc.), data mining, or international trade. They provide crisp or fuzzy parameterized descriptions of the universe of alternatives. On the other hand, in many decisions, costs and benefits occur at different points in time. This brings about intertemporal choices, which may involve an indefinitely large number of periods. However, the literature does not provide a model, let alone a solution, to the intertemporal problem when the alternatives are described by (fuzzy) parameterizations. In this paper, we propose a novel soft set inspired model that applies to the intertemporal framework, hence it fills an important gap in the development of fuzzy soft set theory. An algorithm allows the selection of the optimal option in intertemporal choice problems with an infinite time horizon. We illustrate its application with a numerical example involving alternative portfolios of projects that a public administration may undertake. This allows us to establish a pioneering intertemporal model of choice in the framework of extended fuzzy set theories.

An Economic Theory of Self-Control

Article

Full-text available

Feb 1981

Although many economists, most notably Strotz, have discussed dynamic inconsistency and precommitment, none have dealt directly with the essence of the problem: self-control. This paper attempts to fill that gap by modeling man as an organization. The Strotz model is recast to include the control features missing in his formulation. The organizational analogy permits us to draw on the theory of agency. We thus relate the individual's control problems with those that exist in agency relationships.

Golden Eggs and Hyperbolic Discounting

Article

Full-text available

Feb 1997

David Laibson

Hyperbolic discount functions induce dynamically inconsistent preferences, implying a motive for consumers to constrain their own future choices. This paper analyzes the decisions of a hyperbolic consumer who has access to an imperfect commitment technology: an illiquid asset whose sale must be initiated one period before the sale proceeds are received. The model predicts that consumption tracks income, and the model explains why consumers have asset-specific marginal propensities to consume. The model suggests that financial innovation may have caused the ongoing decline in U. S. savings rates, since financial innovation increases liquidity, eliminating commitment opportunities. Finally, the model implies that financial market innovation may reduce welfare by providing “too much” liquidity.

Kirby KN, Petry NM, Bickel WK. Heroin addicts have higher discount rates for delayed rewards than non-drug-using controls. J Exp Psychol Gen 128: 78-87

Article

Full-text available

Apr 1999

Fifty-six heroin addicts and 60 age-matched controls were offered choices between monetary rewards ($11-$80) available immediately and larger rewards ($25-$85) available after delays ranging from 1 week to 6 months. Participants had a 1-in-6 chance of winning a reward that they chose on one randomly selected trial. Delay-discounting rates were estimated from the pattern of participants' choices. The discounting model of impulsiveness (Ainslie, 1975) implies that delay-discounting rates are positively correlated with impulsiveness. On average, heroin addicts' discount rates were twice those of controls (p = .004), and discount rates were positively correlated with impulsivity as measured by self-report questionnaires (p < .05). The results lend external validity to the delay-discounting rate as a measure of impulsiveness, a characteristic associated with substance abuse.

Measures of Impulsivity in Cigarette Smokers and Non-smokers

Article

Full-text available

Oct 1999

Suzanne H Mitchell

Drug users are thought to be more "impulsive" than non-users. This study examined whether regular smokers are more impulsive than never smokers using personality and behavioral measures of impulsivity. Twenty regular smokers (>/=15 cigarettes/day) and 20 never smokers were recruited. Participants completed five personality questionnaires to assess impulsivity: Adjective Checklist, Barratt's Impulsivity Scale, the Tridimensional Personality Questionnaire, Eysenck's Personality Questionnaire, and the Sensation-Seeking Scale. Participants also performed three behavioral choice tasks designed to assess impulsivity. In the delay task, participants chose between small, immediate and large, delayed monetary rewards. Impulsivity was defined as a relative preference for the small, immediate alternative. In the probability task, participants chose between small, certain and large, uncertain monetary rewards. Impulsivity was defined as a relative preference for the large but more risky alternative. In the work task, participants chose between small monetary rewards obtained by performing a negligible amount of work and a larger amount of money requiring more work. Impulsivity was defined as a relative preference for the smaller, easier alternative. On the personality questionnaires, smokers had statistically higher impulsivity scores on most scales. On the behavioral choice tasks, smokers chose small, immediate money over large, delayed money more frequently, signifying greater levels of impulsivity. There were no differences between the groups' choices on the other tasks. Correlations between questionnaire and task data were small, as were correlations between data from each task. Together, these results indicate that the smokers were more impulsive than never smokers.

Impulsivity and Cigarette Smoking: Delay Discounting in Current, Never, and Ex-Smokers

Article

Full-text available

Nov 1999

Impulsivity is implicated in drug dependence. Recent studies show problems with alcohol and opioid dependence are associated with rapid discounting of the value of delayed outcomes. Furthermore, discounting may be particularly steep for the drug of dependence. We determined if these findings could be extended to the behavior of cigarette smokers. In particular, we compared the discounting of hypothetical monetary outcomes by current, never, and ex-smokers of cigarettes. We also examined discounting of delayed hypothetical cigarettes by current smokers. Current cigarette smokers (n=23), never-smokers (n=22) and ex-smokers (n=21) indicated preference for immediate versus delayed money in a titration procedure that determined indifference points at various delays. The titration procedure was repeated with cigarettes for smokers. The degree to which the delayed outcomes were discounted was estimated with two non-linear decay models: an exponential model and a hyperbolic model. Current smokers discounted the value of delayed money more than did the comparison groups. Never- and ex-smokers did not differ in their discounting of money. For current smokers, delayed cigarettes lost subjective value more rapidly than delayed money. The hyperbolic equation provided better fits to the data than did the exponential equation for 74 out of 89 comparisons. Cigarette smoking, like other forms of drug dependence, is characterized by rapid loss of subjective value for delayed outcomes, particularly for the drug of dependence. Never- and ex-smokers could discount similarly because cigarette smoking is associated with a reversible increase in discounting or due to selection bias.

Opioid deprivation affects how opioid-dependent outpatients discount the value of delayed heroin and money

Article

Full-text available

Oct 2002

A growing literature suggests that excessive temporal discounting of delayed rewards may be a contributing factor in the etiology of substance abuse problems. Little is known, however, about how drug deprivation may affect temporal discounting of delayed rewards by drug-dependent individuals. To examine the extent to which opioid deprivation affects how opioid-dependent individuals discount small, medium and large quantities of delayed heroin and money. Thirteen opioid-dependent individuals maintained on buprenorphine completed a hypothetical choice task in which they choose between a constant delayed reward amount and an immediate reward amount that was adjusted until they expressed indifference between both outcomes. The task was completed for three values of heroin and money rewards during eight sessions under conditions of opioid deprivation (four sessions) and satiation (four sessions). Across conditions, hyperbolic functions provided a good fit for the discounting data. Degree of discounting was significantly higher when subjects were opioid deprived. Consistent with previous findings, degree of discounting was higher for heroin than money and inversely related to the magnitude of the reward. Opioid deprivation increased the degree to which dependent individuals discounted delayed heroin and money. Understanding the conditions that affect how drug-dependent individuals discount delayed rewards might help us understand the myopic choices made by such individuals and help improve treatment outcomes.

Coffey SF, Gudleski GD, Saladin ME, Brady KT. Impulsivity and rapid discounting of delayed hypothetical rewards in cocaine-dependent individuals. Exp Clin Psychopharmacol 11: 18-25

Article

Full-text available

Mar 2003

In this study, crack/cocaine-dependent (CD) and non-drug-using matched control (MC) participants were presented with hypothetical immediate and delayed rewards, with 16 delay conditions ranging from 5 min to 25 years. All participants were presented with hypothetical monetary rewards; however, the CD group was also presented with hypothetical crack/cocaine rewards. The objective value of the rewards ranged from $1 to $1,000. Hyperbolic discounting functions provided a good fit of the data. The CD group discounted monetary rewards at a higher rate than the MC group did, and the CD group discounted crack/cocaine rewards at a higher rate than it did monetary rewards. Moreover, scores on self-report measures indicated greater impulsivity in the CD group when compared with the MC group.

Impulsive Decision Making and Working Memory

Article

Full-text available

Apr 2003

Decision making that favors short-term over long-term consequences of action, defined as impulsive or temporally myopic, may be related to individual differences in the executive functions of working memory (WM). In the first 2 experiments, participants made delay discounting (DD) judgments under different WM load conditions. In a 3rd experiment, participants high or low on standardized measures of imupulsiveness and dysexecutive function were asked to make DD judgments. A final experiment examined WM load effects on DD when monetary rewards were real rather than hypothetical. The results showed that higher WM load led to greater discounting of delayed monetary rewards. Further, a strong direct relation was found between measures of impulsiveness, dysexecutive function,and discounting of delayed rewards. Thus, limits on WM function, either intrinsic or extrinsic, are predictive of a more impulsive decision-making style.

Delay discounting of real and hypothetical rewards

Article

Full-text available

Jun 2003

The degree to which real and hypothetical rewards were discounted across delays ranging from 6 hr to 1 year was explored in a within-subjects design. An adjusting-amounts procedure was used to estimate the subjective value of real and hypothetical rewards at each delay. A hyperbolic discounting function provided a significantly better fit to individual participants' preferences than did an exponential function. No significant effect of reward type on degree of hyperbolic discounting or area under the discounting curves was detected. These findings offer some support for the validity of using hypothetical rewards to estimate discounting rates in substance-abusing and other populations, but caution is suggested because this support is gleaned from a failure to detect an effect of reward type.

Delay Discounting in Current and Never-Before Cigarette Smokers: Similarities and Differences across Commodity, Sign, and Magnitude

Article

Full-text available

Sep 2003

Research has found that nicotine-dependent individuals delay discount monetary gains at a higher rate than matched controls. Delay discount rates, however, have also been found to vary across within-subject variables such as the magnitude of the outcome (e.g., 10 dollars or 1,000 dollars), whether the outcome constitutes a gain or a loss, and the commodity being evaluated (e.g., money or health). The present study comprehensively investigated the differences in delay discounting between current and never-before cigarette smokers and across these within-subject variables. Both groups exhibited a magnitude, sign, and commodity effect. Current smokers' delay discount rates for monetary outcomes, however, were higher than never-before smokers across all magnitudes and both signs. This trend was also found for delayed health outcomes, but failed to reach significance.

Delay discounting by pathological gamblers

Article

Full-text available

Feb 2003

Discounting of delayed rewards by pathological gamblers was compared to discounting of delayed rewards by matched control nongambling participants. All participants completed a hypothetical choice task in which they made repeated choices between dollars 1,000 available after a delay and an equal or lesser amount of money available immediately. The delay to the large amount of money was varied from 1 week to 10 years across conditions. Indifference points between immediate money and delayed money were identified at each delay condition by varying the amount of immediate money across choice trials. For the majority of participants, indifference points decreased monotonically across delays. Overall, gamblers discounted the delayed rewards more steeply than did control participants.

Separate Neural Systems Value Immediate and Delayed Monetary Rewards

Article

Full-text available

Nov 2004
SCIENCE

When humans are offered the choice between rewards available at different points in time, the relative values of the options are discounted according to their expected delays until delivery. Using functional magnetic resonance imaging, we examined the neural correlates of time discounting while subjects made a series of choices between monetary reward options that varied by delay to delivery. We demonstrate that two separate systems are involved in such decisions. Parts of the limbic system associated with the midbrain dopamine system, including paralimbic cortex, are preferentially activated by decisions involving immediately available rewards. In contrast, regions of the lateral prefrontal cortex and posterior parietal cortex are engaged uniformly by intertemporal choices irrespective of delay. Furthermore, the relative engagement of the two systems is directly associated with subjects' choices, with greater relative fronto-parietal activity when subjects choose longer term options.

Effects of short-term nicotine deprivation on decision-making: Delay, uncertainty and effort discounting

Article

Full-text available

Oct 2004

Suzanne H Mitchell

Experimental evidence suggests that when opioid-dependent drug users are deprived of heroin, they become more likely to behave impulsively on a computer task. The current study examined whether nicotine deprivation has similar effects in cigarette smokers, causing an increase in impulsive decision-making. Simultaneously, the impact of deprivation on several other related decision-making tasks was assessed. Eleven smokers (> or = 15 cigarettes/day) participated in two experimental sessions. For one session, they smoked as usual until the session began. For the other, participants did not smoke for 24 hr. Abstinence was verified using levels of breath carbon monoxide and urinary cotinine. During each session, they completed computer tasks that assessed impulsivity by measuring the tendency to choose small, immediate rewards (cigarettes or money) over US dollar 10 available following a delay, as well as tasks in which smokers chose between small, certain, easily obtained rewards and US dollar 10 whose availability was uncertain or required high levels of effort to obtain. Deprivation increased preference for immediate cigarettes over delayed money, but did not alter preference for immediate money over delayed money. These findings indicate that short-term nicotine abstinence does increase impulsive decision-making, but only when the impulsive choice is drug-related. Increases were not related to a general increase in the value of immediate rewards per se or a general increase in aversion to delayed rewards. Decision-making in the other tasks followed a similar pattern: Deprivation increased preference for the cigarette alternative but did not alter the decision-making processes for nondrug rewards.

Tying Odysseus to the Mast: Evidence From a Commitment Savings Product in the Philippines

Article

Full-text available

Jan 2005

We designed a commitment savings product for a Philippine bank and implemented it using a randomized control methodology. The savings product was intended for individuals who want to commit now to restrict access to their savings, and who were sophisticated enough to engage in such a mechanism. We conducted a baseline survey on 1777 existing or former clients of a bank. One month later, we offered the commitment product to a randomly chosen subset of 710 clients; 202 (28.4 percent) accepted the offer and opened the account. In the baseline survey, we asked hypothetical time discounting questions. Women who exhibited a lower discount rate for future relative to current trade-offs, and hence potentially have a preference for commitment, were indeed significantly more likely to open the commitment savings account. Mter twelve months, average savings balances increased by 81 percentage points for those clients assigned to the treatment group relative to those assigned to the control group. We conclude that the savings response represents a lasting change in savings, and not merely a short-term response to a new product.

Cognitive Reflection and Decision Making

Article

Full-text available

Feb 2005
J ECON PERSPECT

Shane Frederick

This paper introduces a three-item "Cognitive Reflection Test" (CRT) as a simple measure of one type of cognitive ability--the ability or disposition to reflect on a question and resist reporting the first response that comes to mind. The author will show that CRT scores are predictive of the types of choices that feature prominently in tests of decision-making theories, like expected utility theory and prospect theory. Indeed, the relation is sometimes so strong that the preferences themselves effectively function as expressions of cognitive ability--an empirical fact begging for a theoretical explanation. The author examines the relation between CRT scores and two important decision-making characteristics: time preference and risk preference. The CRT scores are then compared with other measures of cognitive ability or cognitive "style." The CRT scores exhibit considerable difference between men and women and the article explores how this relates to sex differences in time and risk preferences. The final section addresses the interpretation of correlations between cognitive abilities and decision-making characteristics.

Time Discounting and Time Preference: A Critical Review

Article

Full-text available

Feb 2002
J ECON LIT

This paper discusses the discounted utility (DU) model: its historical development, underlying assumptions, and "anomalies"--the empirical regularities that are inconsistent with its theoretical predictions. We then summarize the alternate theoretical formulations that have been advanced to address these anomalies. We also review three decades of empirical research on intertemporal choice, and discuss reasons for the spectacular variation in implicit discount rates across studies. Throughout the paper, we stress the importance of distinguishing time preference, per se, from many other considerations that also influence intertemporal choices.

Hyperbolic temporal discounting in social drinkers and problem drinkers

Article

Aug 1998

Two studies compared participants, distinguished by their typical alcohol consumption, on the degree to which they discounted the value of delayed, hypothetical amounts of money. Heavy social drinkers in Study 1 and problem drinkers in Study 2 both showed greater temporal discounting than light social drinkers; this difference was stronger in Study 2. Both studies found that a hyperbolic function described temporal discounting more accurately than an exponential function. These results are consistent with extending behavioral theories of intertemporal choice to characterize the determinants of alcohol consumption. The discounting differences also are consistent with more general behavioral economic and economic theories of addiction, although the hyperbolic functional form is inconsistent with the exponential discounting function in economic theory. The drinker groups also differed on impulsiveness and time orientation questionnaires, with light drinkers being less impulsive and more future oriented; however, these measures were not strongly correlated with the measure of temporal discounting.

Is there a daily discount rate? Evidence from the food stamp nutrition cycle

Article

Feb 2005
J PUBLIC ECON

JM Shapiro

Quasi-hyperbolic discounting predicts impatience over short-run tradeoffs. I present a direct non-laboratory test of this implication using data on the nutritional intake of food stamp recipients. Caloric intake declines by 10 to 15 percent over the food stamp month, implying a significant preference for immediate consumption. These findings constitute a rejection of the permanent income hypothesis and are extremely difficult to reconcile with exponential discounting. The data support an explanation based on time preference and reject several alternative explanations, including highly elastic intertemporal substitution. I explore implications for the optimal timing of transfer payments under alternative assumptions about preferences.

Discounting of delayed rewards: the role of age and income

Article

Jan 1994

The Hyperbolic Consumption Model: Calibration, Simulation, and Empirical Evaluation

Article

Aug 2001
J ECON PERSPECT

Laboratory and field studies of time preference find that discount rates are much greater in the short run than in the long run. Hyperbolic discount functions capture this property. This paper presents simulations of the savings and asset allocation choices of households with hyperbolic preferences. The behavior of the hyperbolic households is compared to the behavior of exponential households. The hyperbolic households borrow much more frequently in the revolving credit market. The hyperbolic households exhibit greater consumption income comovement and experience a greater drop in consumption around retirement. The hyperbolic simulations match observed consumption and balance sheet data much better than the exponential simulations.

Excessive discounting of delayed rewards in substance abusers with gambling problems

Article

Aug 1999
DRUG ALCOHOL DEPEN

This study evaluated delay discounting functions of substance abusing problem gamblers, substance abusing non-problem gamblers, and non-problem gambling/non-substance abusing controls. Subjects chose between hypothetical monetary amounts available after various delays or immediately. In one condition, a USUS$1000 reward was delayed at intervals ranging from 6 h to 25 years. At each delay interval, the immediately available rewards varied from USUS$1 to USUS$999 until choices reflected indifference between the smaller immediate and larger delayed rewards. In a second condition, the delayed reward was USUS$100, and immediate rewards varied from USUS$0.10 to USUS$99.90. In all three groups, hyperbolic discounting functions provided a good fit of the data, and the smaller reward was discounted at a higher rate than the larger reward. Substance abusers discounted delayed rewards at significantly higher rates than non-substance abusing controls, and problem gambling substance abusers discounted delayed rewards at higher rates than their non-problem gambling substance abusing counterparts. Discounting rates were not associated with types or recency of drug use. These results provide further evidence of more rapid discounting of delayed rewards in substance abusers, and especially among substance abusers with a comorbid gambling problem. Rapid discounting of delayed rewards may be a feature central to impulse control and addictive disorders.

Is discounting impulsive?

Article

Oct 2003
BEHAV PROCESS

Discounting tasks were used to evaluate whether gambling and non-gambling college students (categorized based on their scores on the South Oaks Gambling Screen) differed in the degree to which they discounted delayed and probabilistic rewards. Hyperbola-like functions provided equally good descriptions of discounting in both groups. Both groups discounted large delayed amounts less steeply than small delayed amounts, whereas both groups discounted large probabilistic amounts more steeply than small probabilistic amounts. Gamblers discounted probabilistic rewards less steeply than non-gamblers, suggesting that gamblers are impulsive in the sense that they are less affected by risk than non-gamblers. However, gamblers did not discount delayed rewards more steeply than non-gamblers. The results argue against the view that impulsivity is a general trait that includes both an inability to delay gratification and a tendency to take risks.

On Second-Best National Saving and Game-Equilibrium Growth

Article

Apr 1968

This chapter highlights the question whether second-best saving is greater or smaller than first-best saving when given future saving is non-optimal from the standpoint of the present generation. The chapter presents the postulation that all generations expect each succeeding generation to choose the saving ratio that is second-best in its eyes. This somewhat game-theoretic model leads to the concept of an equilibrium sequence of saving-income ratios having the property that no generation acting alone can do better and all generations act so as to warrant the expectations of the future saving ratios. The chapter presents a comparison of this equilibrium and the first-best optimum. The concept and calculation of the second-best optimum is of interest even if that analysis does not explain actual national saving because society as a whole has no notion of such an optimum.

Myopia And Inconsistency In Dynamic Utility Maximization

Article

Jan 1955

Robert H. Strotz

This paper presents a problem which I believe has not heretofore been analysed2 and provides a theory to explain, under different circumstances, three related phenomena: (1) spendthriftiness; (2) the deliberate regimenting of one’s future economic behaviour— even at a cost; and (3) thrift. The senses in which we deal with these topics can probably not be very well understood, however, until after the paper has been read; but a few sentences at this point may shed some light on what we are up to.

Discounting of Delayed Rewards: A Life-Span Comparison

Article

Jan 1994

In this study, children, young adults, and older adults chose between immediate and delayed hypothetical monetary rewards. The amount of the delayed reward was held constant while its delay was varied. All thr-ee age groups showed delay discounting; that is, the amount of an immediate reward judged to be of equal value to the delayed reward decreased as a function of delay. The rate of discounting was highest for children and lowest for older adults, predicting a life-span developmental trend toward increased self control. Discounting of delayed rewards by all three age groups was well described by a single function with age sensitive parameters (all R(2)s > .94). Thus, evert though there are quantitative age differences in delay discounting, the existence of an age-invariant form of discount function suggests that the process of choosing between rewards of different amounts and delays is qualitatively similar across the life span.

A Mathematical Theory of Saving

Article

Jan 1928

Frank P. Ramsey

Decision‐Making, Intertemporal

Chapter

Jan 2006

David Laibson

Intertemporal decisions imply trade-offs between current and future rewards. Intertemporal discounting models formalize these trade-offs by quantifying the values of delayed pay-offs.

Cognitive and neurobiological mechanisms of the law of general intelligence

Article

Jan 2006

Christopher F. Chabris

Integrating the mind: Domain general versus domain specific processes in higher cognition. Hove, UK: Psychology Press.

Impatience and grades: Delay-discount rates correlate negatively with college GPA

Article

Dec 2005
LEARN INDIVID DIFFER

Because the rewards of academic performance in college are often delayed, the delay-discounting model of impulsiveness (Ainslie (1975) [Ainslie, G. Specious reward: A behavioral theory of impulsiveness and impulse control. Psychological Bulletin, 82 (4), 463–496] predicts that academic performance should tend to decrease as people place less weight on future outcomes. To test this hypothesis, we estimated (hyperbolic) discount rates for real delayed monetary rewards (US$10 to US$20) using second-price auction procedures with 247 undergraduates at two liberal arts colleges. College GPA was reliably correlated with discount rates, r=−.19 (p=.003), and remained reliable after partialling out SAT scores. The results add to the external validity of the discounting model of impulsiveness, and point to a possible contributor to academic performance of interest in the study of higher education.

Discounting of delayed rewards across the life span: Age differences in individual discounting functions

Article

May 1999
BEHAV PROCESS

The present effort addressed both the issue of the generality of choice models and the issue of possible qualitative developmental change in temporal discounting by examining behavior at the individual level across the life span. Data from individual children, young adults, and older adults who participated in two previous studies were analyzed [Green, L., Fry, A.F., Myerson, J., 1994. Discounting of delayed rewards: a life-span comparison. Psychol. Sci. 5, 33–36; Green, L., Myerson, J., Lichtman, D., Rosen, S., Fry, A., 1996. Temporal discounting in choice between delayed rewards: the role of age and income. Psychol. Aging 11, 79–84]. At all ages, a hyperbola-like function originally proposed by Green et al. (1994) based on group data, provided the best description of individual discounting functions. Two developmental trends were observed. The rate at which individuals discounted the value of delayed rewards decreased with age, and there was a systematic change in the shape of the discounting function. Each of these trends was reflected in a separate parameter of the model. The fact that the same mathematical model described the behavior of individuals of different ages suggests that age and individual differences in the discounting of delayed rewards are primarily quantitative in nature and reflect variations on fundamentally similar choice processes.

Choice And Procrastination

Article

Feb 2001

Recent models of procrastination due to self-control problems assume that a procrastinator considers just one option and is unaware of her self-control problems. We develop a model where a person chooses from a menu of options and is partially aware of her self-control problems. This menu model replicates earlier results and generates new ones. A person might forgo completing an attractive option because she plans to complete a more attractive but never-to-be-completed option. Hence, providing a nonprocrastinator additional options can induce procrastination, and a person may procrastinate worse pursuing important goals than unimportant ones. © 2000 the President and Fellows of Harvard College and the Massachusetts Institute of Technology

Anomalies Intertemporal Choice: Evidence and An Interpretation

Article

Feb 1992

Research on decision making under uncertainly has been strongly influenced by the documentation of numerous expected utility (EU) anomalies—behaviors that violate the expected utility axioms. The relative lack of progress on the closely related topic of intertemporal choice is partly due to the absence of an analogous set of discounted utility (DU) anomalies. We enumerate a set of DU anomalies analogous to the EU anomalies and propose a model that accounts for the anomalies, as well as other intertemporal choice phenomena incompatible with DU. We discuss implications for savings behavior, estimation of discount rates, and choice framing effects.

Addiction and discounting

Article

Sep 1999
J HEALTH ECON

Anne Jensen

In 1988, Becker and Murphy [Becker, G.S., Murphy, K.M., 1988. A theory of rational addiction. Journal of Political Economy, 96, 675-700.] launched a theory in which they proposed that the perspective of rational decision-making could be applied also to cases of addictive behaviour. This paper discusses the theory's assumptions of interpersonal variation and stability in time preferences on the basis of estimates derived from three groups of people with different consumption levels of illegal intoxicants. We find that active injectors of heroin and amphetamine have a higher discount rate than a group reporting that they have never used the substances. Of greater interest, though not in accordance with Becker and Murphy's assumption of stability, we also find that the discount rate among active and former users differs significantly. These findings raise the question of whether a high time-preference rate leads to addiction or whether the onset of an addiction itself alters people's inter-temporal equilibrium.

Needle sharing in opioid-dependent outpatients: Psychological processes underlying risk

Article

Dec 2000
DRUG ALCOHOL DEPEN

Needle sharing contributes to the spread of the human immunodeficiency virus and other health concerns and remains a persistent problem among injection drug users. We determined whether needle sharing may be related to the discounting of the value of delayed outcomes. Outpatients in treatment for heroin dependence indicated preference for immediate versus delayed hypothetical monetary and heroin outcomes in a titration procedure that determined indifference points at various delays. The degree to which the delayed outcomes lost value was estimated with a nonlinear decay model. Participants who agreed to share a needle in a scenario (N=15) discounted delayed money more steeply than did the nonsharing group (N=17). Both groups discounted delayed heroin more steeply than delayed money. Persistent needle sharing may be related to the relative inability of delayed outcomes to impact current behavior. Training to mitigate the effect of delay on outcome value may offer reductions in needle sharing and drug abuse.

Delay discounting of money and alcohol in actively using alcoholics, currently abstinent alcoholics, and controls

Article

Apr 2001

Nancy Petry

Impulsivity is implicated in alcohol dependence, and discounting of delayed rewards may be an objective indicator of impulsiveness. This study evaluated delay discounting functions in alcoholics and controls. It compared discounting rates between different magnitudes ($1000 and $100) and different types (money and alcohol) of rewards. Active alcoholics (n = 19), currently abstinent alcoholics (n = 12) and controls (n = 15) indicated preferences for immediate versus delayed rewards using a titration procedure that determined indifference points at various delays. Four conditions were presented, and the delayed rewards in the four conditions were $1000, $100, 150 bottles of an alcoholic beverage, and 15 bottles of an alcoholic beverage. In all three groups across all four conditions, hyperbolic discounting functions provided a good fit of the data. Linear contrasts, predicting the most rapid discounting rates in active alcoholics, intermediary rates in currently abstinent alcoholics, and the least rapid rates in controls, were significant for three of the four conditions. Alcohol was discounted more rapidly than money. These data provide further evidence of more rapid discounting of delayed rewards in alcohol abusers compared to controls, and especially steep discounting among current users. Rapid discounting of delayed rewards may be a feature related to addictive disorders. A better understanding of how delaying rewards in time impacts their value may have implications for treatment.

Pathological Gamblers, With and Without Substance Use Disorders, Discount Delayed Rewards at High Rates

Article

Sep 2001

Nancy Petry

Pathological gambling is classified as a disorder of impulse control, yet little research has evaluated behavioral indices of impulsivity in gamblers. The rates at which rewards delayed in time are subjectively devalued may be a behavioral marker of impulsivity. This study evaluated delay discounting in 60 pathological gamblers and 26 control participants. Gamblers were divided into those with (n = 21) and without (n = 39) substance use disorders. A hypothetical $1,000 reward was delayed at intervals ranging from 6 hr to 25 years, and immediate rewards varied from $1 to $999. Pathological gamblers discounted delayed rewards at higher rates than control participants, and gamblers with substance use disorders discounted delayed rewards at higher rates than non-substance-abusing gamblers. These data provide further evidence that rapid discounting of delayed rewards may be a feature central to impulse control and addictive disorders, including pathological gambling.

Within-subject comparison of real and hypothetical money rewards in delay discounting

Article

Apr 2002
J EXP ANAL BEHAV

A within-subject design, using human participants, compared delay discounting functions for real and hypothetical money rewards. Both real and hypothetical rewards were studied across a range that included $10 to $250. For 5 of the 6 participants, no systematic difference in discount rate was observed in response to real and hypothetical choices, suggesting that hypothetical rewards may often serve as a valid proxy for real rewards in delay discounting research. By measuring discounting at an unprecedented range of real rewards, this study has also systematically replicated the robust finding in human delay discounting research that discount rates decrease with increasing magnitude of reward. A hyperbolic decay model described the data better than an exponential model.

Alcohol intoxication reduces impulsivity in the delay-discounting paradigm

Article

Mar 2003

To examine the moderating effects of alcohol myopia on cognitive impulsivity in humans using the delay-discounting paradigm. Seventy-six male undergraduate students were randomly assigned to sober, placebo or alcohol conditions. In the delay-discounting task, participants made a series of hypothetical choices between a small, immediate reward and a large, delayed reward. To test the predictions of alcohol myopia theory, participants completed a standard version of the task or one containing cues which impelled the impulsive choice (i.e. preference for the small, immediate reward). Participants also completed a personality measure of impulsivity and the go/no-go task, which assesses motor impulsivity. Intoxicated participants tended to discount delayed rewards at lower rates than sober participants, and blood alcohol level was inversely correlated with delay discounting. The impelling cues did not moderate the effects of alcohol on delay discounting. Alcohol intoxication does not always increase cognitive impulsivity and may lead to more cautious decision-making under certain conditions.

Discounting of money, health, and freedom in substance abusers and controls

Article

Sep 2003
DRUG ALCOHOL DEPEN

Nancy Petry

Impulsivity is implicated in drug dependence, and discounting of delayed events may be an objective indicator of impulsiveness. This study evaluated the manner in which outcomes are devalued over time in drug abusers (n=101) and non-substance abusing controls (n=40). Four conditions were presented in which participants chose between hypothetical outcomes available after various delays or immediately. Two were monetary outcomes, and the other two were non-monetary-months of health or freedom. In all conditions, hyperbolic discounting functions provided a good fit of the data. One hundred dollars were discounted more rapidly than $1000, and freedom was discounted more rapidly than health. Drug abusers discounted all types of delayed outcomes at higher rates than controls, even though they placed equivalent subjective monetary values on freedom and health. Rates of discounting were not correlated across domains. These results replicate prior studies showing that drug abusers discount delayed monetary outcomes more rapidly than controls, and they extend these findings to new domains. The rapid discounting of freedom and health may provide a theoretical framework for understanding illegal and risky health behaviors in drug abusers.

Relative and absolute strength of response as a function of frequency of reinforcement, 12

Article

Aug 1961
J EXP ANAL BEHAV

R. J. Herrnstein

Pathological Gambling Severity Is Associated with Impulsivity in a Delay Discounting Procedure

Article

Nov 2003

Research and clinical expertise indicates that impulsivity is an underlying feature of pathological gambling. This study examined the extent to which impulsive behavior, defined by the rate of discounting delayed monetary rewards, varies with pathological gambling severity, assessed by the South Oaks Gambling Screen (SOGS). Sixty-two pathological gamblers completed a delay discounting task, the SOGS, the Eysenck impulsivity scale, the Addiction Severity Index (ASI), and questions about gambling and substance use at intake to outpatient treatment for pathological gambling. In the delay discounting task, participants chose between a large delayed reward (US $1000) and smaller more immediate rewards (US $1-$999) across a range of delays (6h to 25 years). The rate at which the delayed reward was discounted (k value) was derived for each participant and linear regression was used to identify the variables that predicted k values. Age, gender, years of education, substance abuse treatment history, and cigarette smoking history failed to significantly predict k values. Scores on the Eysenck impulsivity scale and the SOGS both accounted for a significant proportion of the variance in k values. The predictive value of the SOGS was 1.4 times that of the Eysenck scale. These results indicate that of the measures tested, gambling severity was the best single predictor of impulsive behavior in a delay discounting task in this sample of pathological gamblers.

Delay Discounting and Probability Discounting as Related to Cigarette Smoking Status in Adults

Article

Feb 2004
BEHAV PROCESS

This study examined relations between adult smokers and non-smokers and the devaluation of monetary rewards as a function of delay (delay discounting, DD) or probability (probability discounting, PD). The extent to which individuals discount value, either as a function of a reward being delayed or probabilistic, has been taken to reflect individual differences in impulsivity. Those who discount most are considered most impulsive. Previous research has shown that adult smokers discount the value of delayed rewards more than adult non-smokers. However, in the one published study that examined probability discounting in adult smokers and non-smokers, the smokers did not discount the value of probabilistic rewards more than the non-smoker controls. From this past research, it was hypothesized that measures of delay discounting would differentiate between smokers and non-smokers but that probability discounting would not. Participants were 54 (25 female) adult smokers (n = 25) and non-smokers (n = 29). The smokers all reported smoking at least 20 cigarettes per day, and the non-smokers reported having never smoked. The results indicated that the smokers discounted significantly more than the non-smokers by both delay and probability. Unlike past findings, these results suggest that both delay and probability discounting are related to adult cigarette smoking; however, it also was determined that DD was a significantly stronger predictor of smoking than PD.

Heroin and cocaine abusers have higher discount rates for delayed rewards than alcoholics or non-drug-using controls

Article

Apr 2004

To test a prediction of the discounting model of impulsiveness that discount rates would be positively associated with addiction. The delay-discount rate refers to the rate of reduction in the present value of a future reward as the delay to that reward increases. We estimated participants' discount rates on the basis of their pattern of choices between smaller immediate rewards ($11-80) and larger, delayed rewards ($25-85; at delays from 1 week to 6 months) in a questionnaire format. Participants had a one-in-six chance of winning a reward that they chose on one randomly selected trial. Heroin (n = 27), cocaine (n = 41) and alcohol (n = 33) abusers and non-drug-using controls (n = 44) were recruited from advertisements. They were tested in a drug abuse research clinic at a medical school. On average, the cocaine and heroin groups had higher rates than controls (both P < 0.001), but alcoholics did not (P = 0.44). Abstinence was associated with lower rates for heroin abusers (P = 0.03), but not for cocaine or alcohol abusers (both P > 0.50). These data suggest that discount rates vary with the preferred drug of abuse, and that high discount rates should be considered in the development of substance abuse prevention and treatment efforts.

Relationship between education and delay discounting in smokers

Article

Sep 2004
ADDICT BEHAV

Smokers are less educated and are more likely to discount future rewards than nonsmokers. We assessed the relationship between delay discounting and education level in 77 smokers entering smoking cessation treatment. There was an effect of education on computer task and the questionnaire measures of discounting, with participants having no college discounting delayed rewards significantly (P < .01) more than those attending college. Subjects discounted small rewards more than large rewards for both tasks (P < .001). Results show that education level is inversely associated with discounting in smokers.

The rich get richer: Students’ discounting of hypothetical delayed rewards and real effortful extra credit

Article

Jan 2005

The present research compared choices among students with higher or lower grades for rewards that were devalued by imposing a delay to their receipt (Study 1) or by requiring more work for a larger reward (Study 2). In Study 1, students chose between hypothetical and noncontingent smaller immediate or larger delayed monetary rewards. In Study 2, students chose from among different amounts of real, response-contingent academic rewards (extra credit) that required different amounts of work. The results of both studies were similar: The highest scoring students discounted the value of the delayed money less than did their lower scoring counterparts, and the highest scoring students also chose to do and actually did more extra-credit work than lower scoring students did. Differences in the discounting of devalued rewards might represent a fundamental difference between the highest and lower scoring students.

Impulsivity in abstinent alcohol-dependent patients: Relation to control subjects and type 1-/type 2-like traits

Article

Oct 2004
ALCOHOL

Extensive literature has linked behavior control problems in childhood to risk for alcoholism, but impulsivity in alcohol-dependent adults has not been well characterized. Using a variety of laboratory measures of impulsivity, we assessed whether detoxified alcohol-dependent patients [(ADP); n = 130] were more impulsive than control subjects [(CS); n = 41]. In comparison with CS, ADP demonstrated (1) increased rates of commission errors, but not omission errors, in a continuous performance test, (2) a more severe devaluation of delayed reward, (3) increased rates of risky responses in a new risk-taking paradigm, and (4) higher psychometric scores of impulsivity and aggression. Across all subjects, aggressiveness correlated significantly with severity of delay discounting. A post hoc analysis of data obtained for male ADP indicated that, in comparison with patients with late onset of problem drinking and no problem-drinking parent, those ADP with earlier age of problem drinking and who reported a problem-drinking father (type 2-like alcohol dependence) demonstrated faster response latencies and more responses to non-target stimuli (commission errors) in the continuous performance test, as well as higher psychometric aggression. In contrast, these subtypes of male ADP did not differ in delay discounting and risk taking. These findings collectively indicate that, in comparison with CS, ADP are more impulsive in several dimensions, with elevated impulsivity in a working memory task as well as aggressivity characteristic of alcohol-dependent men with type 2-like features.

Discounting Delayed and Probabilistic Monetary Gains and Losses by Smokers of Cigarettes

Article

Dec 2005

Intertemporal Choice

Abstract

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