Evaluating a natural experiment in alcohol policy

Research Summary
This study examines the effects of a dramatic change in alcohol licensing policy on the practice of liquor retailing across a metropolitan urban region. The policy was enacted to remove fixed closing times and to install staggered closing times across regions where it potentially would reduce violent crime and disorder. We found great variation in the extent to which the provisions of the policies were installed as intended.
Policy Implications
The findings suggest that prior consideration for how policy interventions will be applied to real-world settings is important to the validity of research evaluations. Understanding and monitoring variation in the implementation of an intervention is a vital prerequisite to the evaluation of outcomes. Without knowledge of the real-world application of an intervention, researchers risk attributing causal effects to a prevention initiative that might have been absent or only partially received.