Do Firearm Markets Comply with Firearm Restrictions? How the Massachusetts Assault Weapons Ban Enforcement Notice Changed Registered 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 1349 (+560%) within 5 days, followed by a reduction of 211 (-58%) over the next 3 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.