Evaluation is an integral part of a good governance approach to public policy. This principle applies equally to the component of drug policy designed to counter the availability of and access to illicit drugs. Estimation or full costing of drug-related public investment – including both direct expenditure and also indirect costs and impact on public resources – should therefore be a key objective of any evaluation. To evaluate and improve drug policy, it is imperative to know and take note of all possible effects of different interventions and actions. All policies, regardless of purpose or intention, come with a risk of unintended consequences. Public expenditure estimates can be used as a tool for assessing whether the expected or desired results of the policy in question are actually reflected in action, and they constitute a necessary tool for implementing thorough policy evaluations. Public expenditure studies should mirror all relevant activities and policy approaches and may be particularly appropriate in times of austerity. Accurate estimates of public spending will help policymakers plan relevant interventions and allocate necessary funds to authorities in charge of specific aspects of the policy’s implementation. A thorough assessment of drug policy expenditures will also contribute to improved transparency and accountability of public institutions. This publication brings together the findings of wider study conducted by the Pompidou Group in cooperation with the EMCDDA seeking to identify the unintended effects and associated costs of drug control policies. The aim of this publication is threefold. First, increase international awareness about the importance of estimating public expenditure on supply reduction initiatives. Second, stress the importance of harmonizing definitions and increasing availability, comparability and reliability of data as well as methods for sound estimates. Third, contribute to developing sound estimation practices to obtain accurate, complete and reliable drug policy evaluations.

• Costs and Unintended consequences of drug policy