Waiting Periods and the Maturation of a Policy Evidence Base

Swanson and colleagues provide an important contribution to a small but growing evidence base on the effects of firearm purchase waiting periods. Using administrative data from 35 million California residents covered by the Longitudinal Study of Handgun Ownership and Transfer (LongSHOT), the authors examine homicide risk among approximately 1 million first-time handgun purchasers and their cohabitants during the mandatory 10-day waiting period, comparing outcomes with a 4-to-1 matched group of nonpurchasers in the state. The central finding is striking: between 2004 and 2021, 0 homicides occurred among purchasers or their cohabitants during the waiting period. Critics of waiting periods have long characterized them as an arbitrary inconvenience that burdens law-abiding gun owners without meaningfully affecting public safety. This finding—that first-time purchasers face no elevated homicide risk during the delay—speaks to that concern, suggesting that California’s 10-day waiting period does not come at a measurable cost to purchaser safety. With only 13 states currently imposing waiting periods, evidence on this policy is especially valuable.