Local regulation is the next frontier in medical marijuana research:  while it has been the subject of several high-profile court cases, little research has been conducted to study the effects of local regulation on outcomes associated with medical marijuana activities.  While most medical marijuana policy is made on the state level, some states have elected to include provisions explicitly permitting local regulation.  However, it is not immediately clear whether these provisions will lead to differential outcomes.  As local policy makers presumably have more detailed knowledge of their jurisdictions, they may be able to craft regulations that better suit the unique requirements of their communities, including the need for medical marijuana, appropriate limits on distribution mechanisms, and protections to minimize criminal acts associated with marijuana use.  On the other hand, as local governments may not be aware of the effects of their regulations on other communities, they may inadvertently cause externalities that increase the overall societal costs of medical marijuana or reduce the benefits to patients in need of medical marijuana.

I exploit variation in state medical marijuana laws' savings clauses – provisions that explicitly allow for local regulation – to explore whether allowing local regulation has an impact on costs and benefits associated with medical marijuana.  To determine whether allowing local lawmaking is associated with a change in crimes associated with medical marijuana, I consider the effect on adult marijuana possession arrests, juvenile marijuana possession arrests, adult marijuana sales arrests, adult DUI arrests, adult robbery arrests, and adult burglary arrests.  To assess whether local lawmaking is associated with a change in health outcomes associated with medical marijuana, I consider the effect on hospital admissions and utilization, mortality rates for diseases treated with medical marijuana, the rates of use and initiation of marijuana, and treatments for abuse or overdoses of marijuana, alcohol, and prescription drugs.  This research will provide valuable information about what effects allowing variation in local regulation may have on important societal concerns as states continue to adopt medical marijuana laws.