An economic analysis of the determinants of adolescent drug use.

Summary This thesis is based on the assumption that, in order to influence drug use, it is necessary to analyze in detail the determinants of the entry into drug use during adolescence. The tools provided by economic science can shed new light on these determinants. After presenting an overview of public policies to combat tobacco and alcohol in France, we focus on four main themes. First, we look at the monetary resources available to adolescents and show that the amount and origin of these resources are key factors in adolescent drug use. We then study the complementary or substitution relationships that link tobacco and alcohol use. We show that a policy of taxing spirits reduces the consumption of spirits and tobacco by European adolescents, but that the results differ according to the group of European countries. Next, we examine the influence of peer group. We highlight that the likelihood that an adolescent will use drugs increases with the number of peers perceived to be drug users and decreases with peer group size, desire for higher social status, and quality of peer relationships. We conclude with a theoretical analysis highlighting that, beyond traditional policies based on increasing the costs of drugs, considering the benefits of drug use offers new avenues of reflection for primary prevention public policies.