We propose a theoretical model to explain the usage of time-inconsistent behavior as a strategy to exploit others when reputation and trust have secondary effects on the economic outcome. We consider two agents with time-consistent preferences exploiting common resources. Supposing that an agent is believed to have time-inconsistent preferences with probability p, we analyze whether she uses this misinformation when she has the opportunity to use it. Using the model originally provided by Levhari and Mirman (Bell J Econ 11(1):322–334, 1980), (...) we determine the optimal degree of present bias that the agent would like to have while pretending to have time-inconsistent preferences and we provide the range of present-bias parameter under which deceiving is optimal. Moreover, by allowing the constant relative risk aversion class of utility form, we characterize the distinction between pretending to be naive and sophisticated. (shrink)

There has been an intellectual debate at least since the 1960s in business ethics on the role of the media in relation to consumer choice driven by either habits or rationality. If consumers are totally rational, then the global media and global corporations provide just information and knowledge. If consumers are influenced by habit then large corporations and global media can greatly influence consumer choice and create problems of self-control (Ainslie, 1992, Pico Economics: The Strategic Interaction of Successive Motivational States (...) Within the Person, Cambridge University press, Cambridge). In this article, we provide a synthesis and integrated approach to this continuing debate. We provide a more institutional approach to consumer choice based on social conventions, rather than just on individual habits and lapses in self-control. (shrink)

Choice modellers are frequently criticized for failing to provide accurate representations of the neuro-psychological substrates of decisions. Several authors maintain that recent neuro-psychological findings enable choice modellers to overcome this alleged shortcoming. Some advocate a realistic interpretation of neuro-psychological models of choice, according to which these models posit sub-personal entities with specific neuro-psychological counterparts and characterize those entities accurately. In this article, I articulate and defend three complementary arguments to demonstrate that, contrary to emerging consensus, even the best available neuro-psychological (...) models of choice cannot be justifiably given this realistic interpretation. Moreover, I explicate what challenges will continue to hamper neuro-psychological modellers’ attempts to substantiate a realistic interpretation of their models. In doing so, I draw on the literature on scientific modelling to advance the ongoing philosophical discussion concerning the ontological status of the sub-personal entities posited in distinct decision sciences, the resemblance relations that supposedly connect choice models and the neuro-psychological substrates of decisions, and what conditions these models must satisfy to be regarded as realistic representations of their target systems. (shrink)

There are three ways to control our future conduct: by causing it, by manipulating our future selves, or by taking future-directed decisions. I show that the standard accounts of future-directed decisions fail to do justice to their distinctive contribution in intentional diachronic agency. The standard accounts can be divided in two categories: First, those that conflate the operation of decisions with that of devices for either physical constraint or manipulative self-management. Second, accounts that, although they acknowledge the non-manipulative nature of (...) decisions, offer too restrictive a view of source of their effectiveness over time. I argue that a comprehensive view of decisions must acknowledge that there is a variety of ways in which they can be effective, which range from the exercise of rational authority to the reliance on sub-agential psychological propensities. What keeps all of these mechanisms together as possible explanations of the role of decisions in supporting diachronic intentional agency is that these mechanisms operate under a common regulative ideal of diachronic agency: the agent’s reliance on the continuous sense of the stability of the choiceworthiness of the action, regardless of her prior decision to perform it. In light of this regulative ideal, the contribution of effective decisions to diachronic agency is thus in principle dispensable although usually necessary for limited beings like us. (shrink)

A recurring claim in a number of behavioural, cognitive and neuro-scientific literatures is that there is, or must be, a unidimensional ‘common currency’ in which the values of different available options are represented. There is striking variety in the quantities or properties that have been proposed as determinants of the ordering in motivational strength. Among those seriously suggested are pain and pleasure, biological fitness, reward and reinforcement, and utility among economists, who have regimented the notion of utility in a variety (...) of ways, some of them incompatible. This topic deserves philosophical attention for at least the following reasons. Repeated invocation of the ‘common currency’ idiom isn’t merely terminological coincidence because most of the claims are competing explanations either of manifest pattern in choices, or of order in the processes producing choice. We can’t suppose that the different currency claims within each area are compatible, because there are significant obstacles to identifying pairs of members of either the ‘pattern’ or ‘process’ group. There are, finally, seriously opposed positions about the relationships between the pattern facts and the process facts. There are philosophical positions both favouring and opposing a common currency. But direct consideration of the abstract relationships between claims about common currencies across scientific settings, and the arguments for and against these claims, is relatively rare. There is, though, much of philosophical interest to be found here. (shrink)

Extreme sensations – thirst, pain – can focus attention on local consequences at the expense of the overall, perhaps for good evolutionary reasons. Maybe the same phenomenon evolves from prolonged use of addictive substances. The matching law explains mistaken choice, not how a person who has confronted personal catastrophe manages to ignore it in making a locally induced choice.

I discuss various theoretical issues concerning maximizing, matching, and melioration. The model of addiction based on melioration has the key feature that a reduction in drag use increases both the value of drag-taking and the value of conventional activities. I found Heyman's target article stimulating. I don't feel competent to comment on drags but I do have some thoughts, both general and specific, on the theoretical issues.

Heyman's target article is an analytical tour de force, but it makes too hard a distinction between voluntary and driven behavior. It is more fruitful to think about brain and behavior as shifting, interacting “agents,” represented by multiple neural circuits. This has the virtue of better connecting behavioral analysis with wet neuroscience.

For use in applied settings, the melioration model will need to incorporate changes in the shapes of local value functions over time, treat current value as a continuous function of time since previous choices, and take into account discounting of the effects of current behavior on future value. The policy implications of the model for regulating drugs are limited.

Economic models of addiction are choice-based. These models push the choice paradigm too far by modeling addiction as rational, normative behavior. Heyman's target article provides a sensible alternative to this economic approach by emphasizing that addiction is characterized by ambivalence and a perceived loss of self control. However, matching may not be a satisfactory platform on which to build this alternative model. Matching experiments do not provide evidence of ambivalence or perceived loss of self control.

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

Research findings on addiction are contradictory. According to biographical records and widely used diagnostic manuals, addicts use drugs compulsively, meaning that drug use is out of control and independent of its aversive consequences. This account is supported by studies that show significant heritabilities for alcoholism and other addictions and by laboratory experiments in which repeated administration of addictive drugs caused changes in neural substrates associated with reward. Epidemiological and experimental data, however, show that the consequences of drug consumption can significantly (...) modify drug intake in addicts. The disease model can account for the compulsive features of addiction, but not occasions in which price and punishment reduced drug consumption in addicts. Conversely, learning models of addiction can account for the influence of price and punishment, but not compulsive drug taking. The occasion for this target article is that recent developments in behavioral choice theory resolve the apparent contradictions in the addiction literature. The basic argument includes the following four statements: First, repeated consumption of an addictive drug decreases its future value and the future value of competing activities. Second, the frequency of an activity is a function of its relative (not absolute) value. This implies that an activity that reduces the values of competing behaviors can increase in frequency even if its own value also declines. Third, a recent experiment (Heyman & Tanz 1995) shows that the effective reinforcement contingencies are relative to a frame of reference, and this frame of reference can change so as to favor optimal or suboptimal choice. Fourth, if the frame of reference is local, reinforcement contingencies will favor excessive drug use, but if the frame of reference is global, the reinforcement contingencies will favor controlled drug use. The transition from a global to a local frame of reference explains relapse and other compulsive features of addiction. (shrink)

Scandals in companies such as Enron have been a source of great concern in the last decade. The events that led to a global financial crisis in 2008 have heightened this concern. How does one account for executive behaviors that led to such a crisis? This article argues that a conjunction of motive, means, and opportunity creates ‘an ethical hazard’ making questionable executive decisions more probable. It then suggests that corporate unethical behavior can be minimized by creating a process to (...) identify and remove such ethical hazards, and by appointing an ‘ethical hazards marshal.’. (shrink)

It is often argued that future-directed decisions are effective at shaping our future conduct because they give rise, at the time of action, to a decisive reason to act as originally decided. In this paper, I argue that standard accounts of decision-based reasons are unsatisfactory. For they focus either on tie-breaking scenarios or cases of self-directed distal manipulation. I argue that future-directed decisions are better understood as tools for the non-manipulative, intrapersonal division of deliberative labor over time. A future-directed decision (...) to ϕ gives rise to a defeasible exclusionary reason to ϕ. This reason is grounded on the default authority that is normally granted to one’s prior self as an “expert” deliberator. I argue that this kind of exclusionary reason is the only one that can account for the effectiveness of future-directed decisions at shaping our diachronic agency without violating our autonomy over time. (shrink)

In this essay, I review some results that suggest that rational choice theory has interesting things to say about the virtues. In particular, I argue that rational choice theory can show, first, the role of certain virtues in a game-theoretic analysis of norms. Secondly, that it is useful in the characterization of these virtues. Finally, I discuss how rational choice theory can be brought to bear upon the justification of these virtues by showing how they contribute to a flourishing life. (...) I do this by discussing one particular example of a norm - the requirement that agents to honor their promises of mutual assistance - and one particular virtue, trustworthiness. (shrink)

In our target article, we proposed that addiction could be envisioned as misperformance of a decision-making machinery described by two systems (deliberative and habit systems). Several commentators have argued that Pavlovian learning also produces actions. We agree and note that Pavlovian action-selection will provide several additional vulnerabilities. Several commentators have suggested that addiction arises from sociological parameters. We note in our response how sociological effects can change decision-making variables to provide additional vulnerabilities. Commentators generally have agreed that our theory provides (...) a framework within which to site addiction and treatment, but additional work will be needed to determine whether our taxonomy will help identify and treat subpopulations within the addicted community. (shrink)

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

Emotions are Janus‐faced. They tell us something about the world, and they tell us something about ourselves. This suggests that we might speak of a truth, or perhaps two kinds of truths of emotions, one of which is about self and the other about conditions in the world. On some views, the latter comes by means of the former. Insofar as emotions manifest our inner life, however, we are more inclined to speak of authenticity rather than truth. What is the (...) difference? We need to distinguish the criteria of correspondence or appropriateness suitable for authenticity from those that embody the criterion of truth. Furthermore there is also a question about the transitions – among states of mind, and between states of mind and behaviour – that emotions encourage. This realm of transitions concerns rationality. After sketching the relevant distinctions, I will endeavour to justify the view that emotions should be appraised in terms of all three terms. (shrink)

Selfish Goal Theory is compatible with a behaviorally based theory that recognizes mental processes as behaviors. Both envision choices as made by the competition of purposive processes, which are autonomous in that they are not coordinated by an agentic “self.” However, the survival of mental processes – termed “goals” or “interests,” respectively – depends on a well-documented active mechanism: reward.

An imperfect duty such as the duty to aid those in need is supposed to leave leeway for choice as to how to satisfy it, but if our reason for a certain way of satisfying it is our strongest, that leeway would seem to be eliminated. This paper defends a conception of practical reasons designed to preserve it, without slighting the binding force of moral requirements, though it allows us to discount certain moral reasons. Only reasons that offer criticism of (...) alternatives can yield requirements, but our reasons for particular ways of satisfying imperfect duties merely count in favor of the acts in question. When the state is authorized to take over charitable obligations, it should not be seen as enforcing fulfillment of our imperfect duties, but rather as forcing us to help fulfill collective duties that may be substantially modified by transfer to the state, replacing imperfect duties with perfect. Besides the cost to us in freedom of choice there is a moral cost to replacing the virtuous motives of charity with those that tend to accompany paying taxes. However, a compensating feature of state involvement is the fact that its more precise demands come with limits. (shrink)

Suppose you resolve now to resist an expected temptation later while knowing that once the temptation arrives your preference or evaluative assessment will shift in favor of that temptation. Are there defensible norms of rational planning agency that support sticking with your prior intention in the face of such a shift at the time of temptation and in the absence of relevant new information? This article defends the idea that it might be rational to stick with your prior intention in (...) part because of your anticipation of regret in the further future if you were to give in to the temptation. It does this by appeal to the significance of anticipated future regret to the agent ’s present standpoint, and to the role of the agent ’s standpoint in her self-governance. (shrink)

Over the years, many theories have been proposed to account for the aberrant behavior of drug dependent individuals. Heyman posits that the existing theories of drug dependence are inadequate to explain the complex processes inherent in human drug-taking. He proposes that incongruous behaviors that comprise addiction, such as continued drug use in spite of adverse consequences, can be explained by application of the matching law approach. While the matching law theory of addiction explains certain aspects of human behavior, its application (...) to the area of addiction must be subjected to experimental verification. (shrink)

Heyman makes a convincing case that a melioration choice strategy is sufficient to produce addictive behavior. But given a plethora of addiction theories, the question is whether melioration theory is superior to rivals more sophisticated than a simple disease model or operant conditioning account. Heyman offers little direct evidence that melioration actually causes the addictions we observe.

Knowledge of specific instances of melioration does not imply knowledge of the variables controlling behavior. Drug self-administration has been successfully analyzed in terms of standard variables such as the immediacy and magnitude of the drug reinforcer. An appeal to melioration may not be necessary.

The matching law accounts for both addictive behavior and the usefulness of a person's evaluating choices in overall categories. To explain why overall bookkeeping, once learned, does not easily win out over local bookkeeping, another implication of matching is needed: intertemporal bargaining. The role of melioration, though probably important for new addiction is separate.

Ainslie challenges our interpretation of the properties of hyperbolic discount curves in an iterated prisoners’ dilemma model. In this reply, we discuss the emergence of hyperbolic discount functions in the behavioral economics literature and evaluate their properties. Furthermore, we present a summarized version of our IPD model and evaluate Ainslie’s points of contention.

This paper investigates hypotheses drawn from two sources: (1) Belsky, Steinberg, and Draper’s (1991) attachment theory model of the development of reproductive strategies, and (2) recent life history models and comparative data suggesting that environmental risk and uncertainty may be potent determinants of the optimal tradeoff between current and future reproduction. A retrospective, self-report study of 136 American university women aged 19–25 showed that current recollections of early stress (environmental risk and uncertainty) were related to individual differences in adult time (...) preference and adult sexual behavior, and that individual differences in time preference were related to adult attachment organization and sexual behavior. These results are consistent with the hypothesis that perceptions of early stress index environmental risk and uncertainty and mediate the attachment process and the development of reproductive strategies. On this view individual differences in time preference are considered to be part of the attachment theoretical construct of an internal working model, which itself is conceived as an evolved algorithm for the contingent development of alternative reproductive strategies. (shrink)

Philosophy and its descendents in the behavioral sciences have traditionally divided incentives into those that are sought and those that are avoided. Positive incentives are held to be both attractive and memorable because of the direct effects of pleasure. Negative incentives are held to be unattractive but still memorable (the problem of pain) because they force unpleasant emotions on an individual by an unmotivated process, either a hardwired response (unconditioned response) or one substituted by association (conditioned response). Negative incentives are (...) divided into those that are always avoided and those that are avoided only by higher mental processes—archetypically the passions, which are also thought of as hardwired or conditioned. Newer dichotomies within the negative have been proposed, hinging on whether a negative incentive is nevertheless sought (“wanted but not liked”) or on an incentive's being negative only because it is confining (the product of “rule worship”). The newer dichotomies have lacked motivational explanations, and there is reason to question conditioning in the motivational mechanism for the older ones.

Both experimental findings and the examination of common experience indicate that even the most aversive experiences, such as pain and panic, do not prevail in reflex fashion, but because of an urge to attend to them. The well-established hyperbolic curve in which prospective rewards are discounted implies a mechanism for such an urge, as well as for the “lower” incentives in the other dichotomies. The properties of these lower incentives are predicted by particular durations of temporary preferences on a continuum that stretches from fractions of a second to years. (shrink)

The ten vulnerabilities discussed in the target article vary in their likelihood of producing temporary preference for addictive activities automatic” habits discussed here.

Social dilemmas occur when individuals make choices that are in their own best interest but not in the interest of society as a whole. Intrapersonal dilemmas occur when people make choices that are in the best interest of themselves at the moment of choice, but not in the best interest of themselves in the long run. A number of writers have observed that we can usefully model this self-defeating behavior by treating each individual as an aggregate of selves which have (...) competing interests, like the individual selves in a population. We undertake to synthesize and extend these contributions, applying the theory of intrapersonal dilemmas to addiction and procrastination, and discuss how the concept of multiple selves can explain why people attempt to control their behavior by imposing costs or constraints on themselves in the future, and how it can also help us develop new strategies of (personal) behavior control. (shrink)

Two issues are raised. (1) What is the nature of the drug effect Heyman thinks confers value to drugs? (2) What is the evidence that drug use decreases the value of drugs and of conventional incentives over the long-term? There is considerable evidence for the opposite; a persistent increase in the sensitivity of neural systems that mediate drug value.

Heyman's model explains the irrationality of addictive behavior, but it does not satisfactorily answer the question of whether this behavior is voluntary because it does not address the issue of the choice of preference functions. Furthermore, although Heyman disconfirms the disease model of addiction, this does not resolve the issue of whether addiction should be classified as a mental illness.

Heyman's view that addiction can be viewed as a natural outcome predictable by melioration and the matching law is provocative. Remaining to be explained more fully, however, are exactly how his view is an improvement on other reinforcement-based accounts. Included in these elaborations should be an account of how different “bookkeeping schemes” are developed and controlled and what new approaches to treatment and prevention of drug addiction are indicated.

This paper examines why fundamental freedoms are so unevenly distributed across the earth. Climato-economic theorizing proposes that humans adapt needs, stresses, and choices of goals, means, and outcomes to the livability of their habitat. The evolutionary process at work is one of collectively meeting climatic demands of cold winters or hot summers by using monetary resources. Freedom is expected to be lowest in poor populations threatened by demanding thermal climates, intermediate in populations comforted by undemanding temperate climates irrespective of income (...) per head, and highest in rich populations challenged by demanding thermal climates. This core hypothesis is supported with new survey data across 85 countries and 15 Chinese provinces and with a reinterpretative review of results of prior studies comprising 174 countries and the 50 states in the United States. Empirical support covers freedom from want, freedom from fear, freedom of expression and participation, freedom from discrimination, and freedom to develop and realize one's human potential. Applying the theory to projections of temperature and income for 104 countries by 2112 forecasts that (a) poor populations in Asia, perhaps except Afghans and Pakistanis, will move up the international ladder of freedom, (b) poor populations in Africa will lose, rather than gain, relative levels of freedom unless climate protection and poverty reduction prevent this from happening, and (c) several rich populations will be challenged to defend current levels of freedom against worsening climato-economic livability. (shrink)

A climate that is too cold to grow crops for part of the year demands foresight and self-control skills. To the extent that a culture has developed intertemporal bargaining, its members will have more autonomy, but pay the cost of being more compulsive, than members of societies that have not. Monetary resources will be a consequence but will also be fed back as a cause.

The models of internal self-control that have recently been proposed by behavioral economists do not depict motivational interaction that occurs while temptation is present. Those models that include willpower at all either envision a faculty with a motivation (“strength”) different from the motives that are weighed in the marketplace of choice, or rely on incompatible goals among diverse brain centers. Both assumptions are questionable, but these models’ biggest problem is that they do not let resolutions withstand re-examination while being challenged (...) by impulsive alternatives. The economists’ models all attempt to make a single equilibrium preference predictable from a person’s prior incentives. This was the original purpose of these models’ hyperboloid (“β–δ”) delay discount functions, which have been widely justified by the assumption that a person’s intertemporal inconsistency (impulsiveness) can be accounted for by the arousal of appetite for visceral rewards. Although arousal is clearly a factor in some cases of intertemporal inconsistency, it cannot be blamed for others, and furthermore does not necessarily imply hyperboloid discounting. The inadequacy of β–δ functions is particularly evident in models of internal self-control. I have reviewed several of these models, and have argued for a return to pure hyperbolic discount function as originally proposed, the relatively high tails of which can motivate a recursive process of self-prediction and thereby the formation of self-enforcing intertemporal contracts. Such a process does not require a separately motivated faculty of will, or incompatible goals among brain centers; but it also does not permit the prediction of unique preferences from prior incentives. (shrink)

Suppose I am now making plans for next summer’s vacation. I can spend a week in Rome or on the Riviera, but not both. Either choice would be excellent, but after weighing various pros and cons, I decide that for my purposes Rome would be better. If I am rational, then, I must choose Rome. It is an assumption of standard decision theory that rationality requires maximizing: trying to get the maximum amount of whatever form of value we are after (...) (usually construed as “utility”). An alternative has been proposed, under the heading of “satisficing” – being satisfied with what suffices, as it were, or settling for an option that is “good enough” – but this may seem rational only when there are costs to determining which option is best that diminish the value of choosing it, to the point where the choice of a less good option really amounts to maximizing. Where there is no serious cost, even in time and effort, to getting hold of something better – a vacation in Rome rather than the Riviera – how could it be rational to turn it down? If we pay attention to the temporal standpoint from which a choice is made, though, satisficing makes good sense. It accords with our common appeal to thresholds: adequate levels of satisfaction or value, such that getting above them is not necessary, though it might be nice. Once we have reached a threshold, it is rational – meaning rationally permissible – to stop. Pushing further toward the best may also be permissible but is not rationally required, where we already have a good enough option in hand. So if offered a chance to move to Rome while already settled happily on the Riviera, I would not be irrational to turn the offer down, even if I grant that accepting it would make my vacation even better. (shrink)

The target article emphasizes the relationship between a matching law-based theory of addiction and the disease model of addiction. In contrast, this response emphasizes the relationship between the matching law theory and other behavioral approaches to addiction. The basic difference, I argue, is that the matching law specifies that choice is governed by local reinforcement rates. In contrast, economics says that overall reinforcement rate controls choice, and for other approaches there are other measures or no clear prediction at all. The (...) response also differs from the target article in that there is more emphasis on the finding that stimulus conditions determine whether choice is under local or overall reinforcement rate control. (shrink)

Addictive behavior has never seemed rational because it persists in spite of drastic aversive consequences. This is a particular problem for models of addiction such as operant psychology which hold that behavior is controlled by its consequences. Inspite of claims to the contrary, Heymans target article illustrates how operant psychology resolves this contradiction. By using the matching law, Heyman suggests a mechanism that explains why delayed aversive events may not control behavior, and a conceptual framework in which we can understand (...) successful therapies. (shrink)

Heyman's target article makes a strong case for a behavioral approach to addiction, yet some important assumptions require justification, and promising behavioral alternatives to the author's melioration approach should be considered. In particular, the behavioral economic approach to addiction appears well developed and comprehensive. How does the melioration approach complement or improve on a behavioral economic account?

Heyman's analysis of addiction suggests that drug taking is irrational. The irrationality of drug taking, however, may depend on the acceptance of mainstream society's view of what is valuable. Consideration of the addict's viewpoint and cultural aspects of drug taking may be useful in trying to fathom the “rationality” of drug taking.

The conflict between drug and conventional rewards leads to a paradox: Sanctions against drug use decrease access to conventional rewards and push drug users toward drug abuse, whereas increased access to the rewards of family, friends, and work may help reduce drug abuse. Lack of control is not specific to drug addiction and is unlikely to yield to a shift in bookkeeping.