Drugs policy: what should we do about cannabis?

Public policy has failed to prevent large-scale consumption of cannabis in most developed countries. So what, if anything, should we do to change the policy environment? Cannabis consumption is unambiguously harmful in several ways, but this does not automatically justify the prohibitionist policy dictated by the international drugs conventions. This paper sets out the arguments for policy intervention in the cannabis market and reviews the directions of policy change that have been called for. We argue that existing theoretical insights and empirical evidence give little compelling reason to prefer prohibition to the alternative of legalization of cannabis with harms controlled by regulation and taxation. Given this conclusion and the much wider prevalence of cannabis than of harder drugs, a reasonable way forward is to remove cannabis production and consumption (but not trade) from the current prohibitionist UN drug control treaties, to allow countries to adopt their own policies, thus generating new evidence on the potential impacts of a wider range of policy.