Review of methodologies of evaluating effects of drug-related legal changes
This paper analyses primary studies that examine the consequences of drug law changes, and describes their approach and methodologies. They were categorised as changes to laws addressing illegal use and possession, changes in laws regulating legal use and possession, and enforcement strategies of existing laws. Across these studies, the authors identify five types of evaluation questions and indicators, three types of data sets, and two study designs that have been used. Evaluations may highlight the intended and unintended effects of a legal change, but there can also be unexpected effects, and the full picture will describe all of these. Evaluations should not be taken as proof that one law is better than another; an objective and authoritative study result will be obtained by good design, questions and indicators that reflect a wide variety of concerns, and appropriate data sets.