What Can Be Learned from Cross-National Comparisons of Data on Illegal Drugs?

There has been relatively little effort at cross-national analysis of data concerning drug policy, though there is growing variation in how nations deal with illegal drugs. Systematic accounts of barriers to, and opportunities for, making comparisons are scarce. Comparisons of drug use prevalence, the focus of most cross-national studies, are undermined by fundamental and unacknowledged methodological differences. Prevalence is a poor measure of drug problems, but more appropriate indicators, such as drug-related crime and morality, are generated by institutional and legal systems that differ across countries, making them even more difficult to compare. The same is true of intensity of enforcement; besides problems of creating comparable arrest, conviction, and incarceration data, there is difficulty in generating an appropriate denominator of offenses. Collaboration among national data collection programs can help somewhat, but substantial progress will depend on harmonization of basic measurement systems, such as arrests and incarceration and on more subtle measures such as the prevalence of problem drug use.