Addiction and Self-Control

Mele, Alfred. 1996. "Addiction and Self-Control." Behavior and Philosophy 24 99-117. 

All explanations of addiction and policies on substances of abuse will have to confront the complex clinical realities. The development of addiction involves characteristic changes in motivation and self-control important both to the individual and to society. The frequency of drug taking is a central factor in this process but not the sole factor. Others relate to societal influences and others again to upbringing or biological dispositions. The clinical phenomenology is mostly described by concepts such... 

Other forms of behavior have been shown to be similar to the classical addictions. Some people seem unable to control their use of credit cards or, more generally, to control their impulse to obtain goods in a pattern that is detrimental to their economy and, often, their social life. Others seem to be sexually insatiable or at least unable to abstain from the pursuit of new and ever more frequent sexual encounters. These types of behavior are often named manias, obviously to illustrate a state of mind characterized by impoverished self-insight and self-control. The common phenomenological feature of these cases—pathological gambling, eating... 

The crucial intuition driving these calibration results is the incremental nature of most addictive behavior. At each point in time, people choose whether to indulge now, and the cumulative effect of these decisions determines whether people get and remain addicted. With self-control problems, a sequence of incremental decisions can lead to behavior very different from how people would behave if committing up front to a lifetime path of behavior. In a rational choice model, in contrast, the incremental nature of addiction is irrelevant. If people know exactly what the future holds, and have no self-control problems, then people become addicted only if that is the optimal lifetime path of behavior. 

Let me press this point a bit further. I am told that it is possible for a well-supplied heroin addict to live an otherwise healthy and productive life. (It appears to be otherwise with cocaine and amphetamines.) In any case, imagine that this is so for a certain severely addictive substance,, and that in a certain culture, otherwise similar to ours, the use of S is not only tolerated but respected as highly spiritually beneficial. This culture regards the dependency on this substance, which is to say, the vulnerability to various kinds of diminished self-control, as a small price to pay for the enrichment of human life provided by S. Fortunately, S is easily obtainable, perhaps even subsidized by the society for religious reasons. 

The assessment of addiction as a form of slavery depends as much on norms regarding the value of addictive dependencies as from concerns about self-control per se. We tend to see them as demeaning or destructive rather than as possible sources of worthwhile human activity. For this reason, we tend to expect people to avoid those conditions and see the plight created by those conditions as the individual s own fault. 

MANY OBSERVERS suspect that self-control problems and related time inconsistencies play an important role in the consumption of addictive, products, leading people to develop and maintain addictions against their long-run interests. People often consume addictive products despite an expressed desire to quit. For many people, it would appear that the long-run harm caused by an addiction outweighs its short-run benefits. In extreme cases, people destroy their lives with harmful addictions. Our goal in this chapter is to carefully explore the role that self-control problems—and people s awareness of those problems— play in harmful addictions. To do so, we develop a formal model of the decision to consume addictive products that explicitly incorporates a time-inconsistent taste for immediate gratification. 

Economists have proposed rational choice models of addictive behavior (Becker and Murphy 1988 Becker, Grossman and Murphy 1991,1994). These models characterize how consuming harmful addictive products can decrease future well-being while at the same time increasing the desire for those products in the future. Because these models consider only time-consistent agents, however, they a priori rule out the possibility of self-control problems. 

Like the rational choice models of addiction, our model assumes that the choice to consume an addictive product is volitional, in the sense that people balance their current desire for the addictive product against their perceptions of the future consequences of current consumption. Our model is quite different, and less extreme, than rational choice models, however, because it assumes that people may be overattentive to their immediate gratification (that is, they may have self-control problems) and... 

In addition to the implications of having self-control problems, we also focus on the implications of whether people are aware of their own future self-control problems. We examine two extreme assumptions Sophisticated people are fully aware of their future self-control problems and therefore know exactly how they will behave in the future and naive people are fully aware of their future self-control problems and therefore believe they will behave in the future exactly as they currently would like themselves to behave. By systematically comparing sophisticates, naifs, and time-consistent agents (whom we refer to as TCs), we can examine the role of self-control problems in addiction and delineate how predictions depend both on self-control problems per se and on assumptions about foresight. 

We begin with a stationary model of addiction, in which the temptation to hit can depend on the addiction level but otherwise remains constant over time, which allows us to identify some basic insights. We first ask what is the direct implication of self-control problems by comparing TCs and naifs. In the stationary model, naifs are always more likely to hit than TCs. Since naifs are unaware of future self-control problems, they perceive that they will behave exactly like TCs in the future and... 

We next ask what are the implications of being aware of future self-control problems by comparing naifs and sophisticates. We identify two effects. First, sophistication about future self-control problems can make people pessimistic about future behavior (that is, they believe in general that they will hit more often than they would if they had no self-control problem). We refer to this phenomenon as the pessimism effect. Second, sophistication about future self-control problems may make people realize that they will resist future temptations only if they resist temptation today. We refer to this phenomenon as the incentive effect. Because the habit formation property of addictive products implies that current indulgence has larger future costs the more people expect to refrain in the future, pessimism about future behavior tends to exacerbate overconsumption due to self-control problems. The incentive effect, in contrast, tends to mitigate overconsumption due to self-control problems. Hence, whether sophisticates hit more or less often than naifs depends on the relative magnitudes of the pessimism and incentive effects. 

Let U,(k a) be people s period-1 continuation (long-run) utility as a function of their addiction level in period t, kt, and their strategy, a. Long-run utility represents intertemporal preferences from some prior perspective, so that self-control problems (that is, p) are irrelevant People s long-run preferences are represented by equation (6.1) when p = 1, and therefore TCs, naifs, and sophisticates have identical long-run utilities. A useful way to write U,(kr a) is... 

In this example, naifs indulge in the addictive activity more than TCs. This result turns out to be quite general Self-control problems combined with a belief that in the future they will not have such problems always leads people to overconsume addictive products. Indeed, the following result follows directly from definitions 3 and 4 For any contingency, if TCs hit, then naifs hit, and therefore if naifs refrain, then TCs refrain. 

That naifs indulge more in example 2 than in example 1 reflects how the youth environment can be problematic for naifs, who give in to large youthful temptations under the false belief that they will later quit. In example 2, in their youth, naifs (like sophisticates) would most like to hit in their youth and refrain thereafter. Since naifs do not foresee future self-control problems, they choose to follow this path in their youth but they end up never quitting and, therefore, suffer a lifetime of addiction. 

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