Rebuttal of Ayres and Donohue Claim of "More Guns, More Crime"

A new article has recently appeared in a peer-reviewed journal on the issue of whether "shall issue" right-to-carry concealed weapons laws (reqwuiring authorities to issue concealed-weapons weapons to anyone who applies without a criminal record or history of mental illness). The article, found here, concludes that such laws are generally beneficial.

The article, written by Carlisle Moody and Thomas Marvell, rebuts the 2003 article in the Stanford Law Review by Ian Ayres and John Donohue. Ayres and Donohue found (contrary to the seminal work of John Lott and David Mustard) that shall-issue laws actual lead to an overall increase in crime. Here is how Moody and Marvell describe their findings:

While reading Ayres and Donohue's 2003 article in the Stanford Law Review, we noticed that their analysis did not prove what they said it proved. They claimed that their model proved that shall-issue laws increased crime. Our conclusions are as follows.

Many articles have been published finding that shall-issue laws reduce crime. Only one article, by Ayres and Donohue who employ a model that combines a dummy variable with a post-law trend, claims to find that shall-issue laws increase crime. However, the only way that they can produce the result that shall-issue laws increase crime is to confine the span of analysis to five years. We show, using their own estimates, that if they had extended their analysis by one more year, they would have concluded that these laws reduce crime. Since most states with shall-issue laws have had these laws on the books for more than five years, and the law will presumably remain on the books for some time, the only relevant analysis extends beyond five years.

We extend their analysis by adding three more years of data, control for the effects of crack cocaine, control for dynamic effects, and correct the standard errors for clustering. We find that there is an initial increase in crime due to passage of the shall-issue law that is dwarfed over time by the decrease in crime associated with the post-law trend. These results are very similar to those of Ayres and Donohue, properly interpreted.

Moody and Marvell's findings seem plausible to me.

Related Posts (on one page):

  1. Update on the More Guns, Less Crime Debate
  2. Rebuttal of Ayres and Donohue Claim of "More Guns, More Crime"