Effects of implementing permissive campus carry laws on rates of major violence at public colleges and universities.

Background: Following the Supreme Court's decision in New York State Rifle & Pistol Association, Inc. v. Bruen, which ruled a New York concealed-carry permitting requirement unconstitutional, laws restricting the public carrying of firearms in "sensitive places," like college campuses, have received increasing attention. However, there is little evidence for whether permissive campus carry policies increase firearm violence or, via deterrence, reduce general crime on campus. We estimated the effect of implementing state laws allowing the carry of firearms on public college and university campuses on rates of violent crime and burglary.

Methods: Arkansas, Georgia, and Texas, containing 106 public institutions, implemented permissive campus carry laws in 2017, 2017, and 2016, respectively. Control institutions were all those in states that did not allow the carry of firearms on college campuses for the entire study period (2006-2019) (n = 324 institutions, 21 states). The rates of major violence and burglary per 1,000 enrolled students was obtained from the Office of Postsecondary Education Campus Safety and Security Statistics website. We use two-way fixed effects difference-in-differences models to estimate state-specific effects and a modified difference-in-differences approach that accounts for variation in treatment timing to generate an overall estimate.

Results: Differences in rates of major violence and burglary were not statistically distinguishable from zero in our main models and sensitivity analyses. The overall estimated difference in the rate of major violence following policy implementation was - 0.01 (- 0.113, 0.093). For burglary, we estimated a difference of - 0.02 (- 0.147, 0.106). Violence rates trended upward in treated states in the last exposure period, but differences were not consistently distinguished from the null.

Conclusions: This study does not find significant changes in crime rates following state implementation of permissive campus carrying laws. Decision-makers might therefore consider other factors such as the opinions of students, faculty, and staff regarding campus carry policies and feelings of safety, potential impacts on instructional quality and student engagement, and potential impacts on accidental or self-directed harm.