3. Using Supply Indicators in the Evaluation of Drug Supply Reduction – Challenges and Opportunities

Supply reduction interventions are seen as standard components of illicit drug policies. Evaluating them requires not only understanding drug markets and the associated crime, but also measures of the activities undertaken to tackle them. A wide range of indicators are needed but the illicit nature of the drug market limits the data available and makes interpretation challenging.

This presentation provides examples of the limitations and challenges in using supply indicators for evaluation before discussing options for improvements. It is based on the long-term work of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), in collaboration with a wide range of international experts, to improve the collection, analysis and reporting of supply-related data within the European Union and other partner countries.

Addressing the wide variety of data limitations identified and the variety of uses of data in the evaluation process requires a long-term, structured programme. The EMCDDA supply indicator work utilises a conceptual framework that groups indicators within three broad thematic areas: drug markets, drivers and facilitators; drug-related crime, harms and other consequences; and drug supply reduction and responses. Within each area, priorities for improvement can be identified and three possible types of action considered: improving the quality of existing data; extending the range and scope of data collected; and enhancing analysis.

The structured approach described may have wider application with the potential to provide a richer picture of drug markets, and aid efforts to evaluate drug supply reduction policies and lead to incremental improvement over time.