Do Firearm Markets Comply with Firearm Restrictions? How the Massachusetts Assault Weapons Ban Enforcement Notice Changed Firearm Sales

How well do firearm markets comply with firearm restrictions? The Massachusetts Attorney General issued an Enforcement Notice in 2016 to announce a new interpretation of the key phrase copies and duplicates in the state's assault weapons ban. The Enforcement Notice increased assault rifle sales by 1,349 (+560%) within five days, followed by a reduction of 211 (-58%) over the next three weeks. Assault rifle sales were 64-66% lower in 2017 than in comparable earlier periods, suggesting that the Enforcement Notice reduced assault weapon sales but also that many banned weapons continued to be sold. Overall, the results show how quickly policy can affect the firearm market and provide an upper bound on firearm market compliance with assault weapon restrictions.