Ayres and Donohue have sent a letter to the St. Louis Post-Dispatch, replying to Lott's 21 July letter. I agree with their description of Lott's behaviour as dishonest.
On July 21, 2003, researcher John Lott wrote a letter to the editor in which he tried to shore up support for his now discredited theory that state adoption of laws allowing citizens to carry concealed handguns will lower crime. Although he refuses to acknowledge this fact, we showed in a recent article published in the Stanford Law Review that when the coding errors in his own data set are corrected, his own regressions show no such drop in crime. Lott tries to distract the readers by stating that our study illustrating his coding errors was only published in a law review, rather than in a peer-reviewed journal. But since Lott knows that merely correcting his errors did eliminate his finding, it is dishonest for him not to concede the fact. How can we assert that Lott knows that we correctly identified coding errors in his data? Because he had put his data set on his own web page before we found his errors, and he has now gone in and quietly corrected the errors that we identified. Lott should put an end to the charade and acknowledge that his own most recently published regressions, when corrected, offer no support for the more guns, less crime hypothesis. As the latest, peer-reviewed, article on this topic by researchers Tomislav Kovandzic and Thomas Marvell states: "we find no credible statistical evidence that increases in permit rate growth (and presumably more lawful gun carrying) leads to substantial reductions in violent crime, especially homicide. Similar to Ayres and Donohue (2003), we find that our best, albeit admittedly imperfect, statistical evidence indicates that increases in permit rate growth may actually lead to slight increases in crime."
Professor Ian Ayres, Yale Law School
Professor John Donohue, Stanford Law School