The impact of drug policy changes on cannabis availability and use among adolescents: evidence from Europe

Cannabis is the most used illicit drug and accounts for the largest share of the illicit drug market. To tackle this longstanding problem, a broad set of reforms to national cannabis control policies have been implemented in Europe, but their effectiveness in achieving the desired results is still unclear. This paper analyses the association between selected categories of cannabis policy reforms and changes in cannabis availability and use among adolescents. Data from 20 European countries across 15 years were drawn from a novel database of the European school Survey Project on Alcohol and other Drugs. We estimate the influence of policy changes on reported access to cannabis and different frequencies of use. Our identification strategy is based on a difference-indifference model, which application is allowed by the fact that only thirteen out of the twenty countries included implemented relevant reforms. Our results suggest that selected categories of reforms influence the availability and prevalence of cannabis among adolescents. In particular, some forms of restrictive intervention reduce the general prevalence of use and more liberal reforms seem to cause an increase in the share of students approaching cannabis. However, none of them seems able to influence the consumption habits of frequent users.