Temporary gains and permanent costs in methamphetamine precursor control

James Cunningham and co-authors did pioneering work in evaluating the impact of precursor control on methamphetamine markets and related harms. We discuss their studies, as well as others that followed, and review what is known of precursor control's short-run and long-run impacts. We interpret the evidence to suggest that precursor control was likely cost-effective initially. However, long-run supply adjustments by illicit meth producers weakened the controls' efficacy. Meanwhile, regulations on legal consumers of cold medications were permanent and unavoidable, which may have closed the gap on the positive net benefits that had accrued initially in the short run. Our review underscores the challenges policymakers face in achieving their goals when supply can adjust long-term, but non-participants in illegal markets cannot.