Guns, Privacy, and Crime

We investigate the impact of an information shock – the public exposure of the names and addresses of holders of handgun carry permits – on criminals’ propensity to commit crimes. In December 2008, a Memphis, TN newspaper published a searchable online database of names, zip codes, and ages of Tennessee handgun carry permit holders. Once news of the database publication spread, an intense and acrimonious debate arose. Permit holders flooded the newspaper demanding its removal, on the grounds that the database invaded their privacy. Gun rights associations argued that the newspaper had put law-abiding gun owners at risk, giving criminals a pathway to burglarize their homes. The newspaper responded by suggesting that any criminal who perused the database would, in fact, be more likely to avoid households they believed to contain guns. We use detailed crime and handgun carry permit data for Memphis to estimate the impact of the database publication on different types of crime. We find that crimes more likely to be affected by knowledge of gun ownership such as burglaries increased more significantly, after the database was publicized, in zip codes with fewer gun permits, and decreased in those with more gun permits. We find no comparable effect for crimes that are usually not premeditated, like assaults or shootings, or in nearby areas and comparable cities that were not covered by the published database. We also find no evidence that publishing the identities of gun permit holders led to a relative increase in crimes aimed at stealing their weapons. Our findings contribute to the debate on gun control and crime, and to the debate on the privacy and security trade-offs associated with the public dissemination of governmental data. ∗The authors wish to thank Ralph Gross, Sajit Kunnumkal, Pratik Parikh, and Ganesh Raj for excellent research assistance; Michael Erskine and the staff of the Commercial Appeal for their collaboration; Colin Drane for providing and discussing www.spotcrime.com data; Alfred Blumstein, Daniel Nagin, Lamar Pierce, Mel Stephens, K.B. Turner, Hal Varian, and participants in workshops at Harvard University, George Washington University, and Katholieke Universiteit Leuven for insightful comments. †Heinz College, Carnegie Mellon University, Pittsburgh, PA; [email protected]. ‡MIT Sloan School of Business, MIT, Cambridge, MA; [email protected].