Drug use and dependence: an economic analysis.

Summary Are the economic sciences capable of explaining the diversity of drug use, which varies over time, according to the individual and the product? The theory of rational addiction (Becker and Murphy, 1988) is based on a hypothesis of habit formation which does not allow us to grasp the specificity of psychotropic drugs compared to more ordinary goods such as games. Drug use is particularly harmful when it reduces the ability to project into the future or when it destroys, directly or indirectly, the taste for certain activities. The hypothesis of variability of time preference allows us not only to account for the first stylized fact, but also to establish conceptual equivalences with the sociology of drug addiction. Furthermore, we develop a model of the drug as a totalitarian good, in which the user learns to love only the drug to the detriment of any other activity. This model predicts most of the phenomena characteristic of heavy addictions, in particular the existence of adjustment costs, socio-economic marginalization and cycles of consumption. We conclude with an economic definition of addiction. We then propose an analysis of the consumption of tobacco, alcohol and cannabis by French adolescents, by applying the techniques of duration and "double-hurdle" models to the Inserm survey (1993). Then we study the effects of health information on cigarette consumption. For this, we build a model that treats cigarettes as an addictive and totalitarian good, since they are addictive and constitute a risk, to be determined from various information, for the health capital.