Other research, by David Olson at Loyola University and Michael Maltz at the University of Illinois, found that when law-abiding citizens carried concealed handguns, criminals were much less likely to carry guns. In fact, they found gun murders fell by 20 percent.
This prompted a rebuke from Michael Maltz, who wrote:
In an effort to promote laws permitting the carrying of concealed weapons, in the April 24th Dispatch John Lott supports his own position by citing research I did with David Olson, purporting to show that these laws reduce homicide. In doing so, Lott bends the truth so much that he breaks its back. Specifically, Lott is well aware of a paper Joseph Targonski and I published in September of last year that points out that the data that we used in that study was problematic and should not be relied upon. The conclusion of our more recent paper is that Lott's data (and ours) were so error-laden that they cannot be used with any degree of reliability.
So how did Lott change his op-ed in response to this? Does he withdraw the claim? No, he replaces the passage with:
Several studies find that as law-abiding citizens are allowed to defend themselves, criminals are much less likely to carry guns.
This seems to be Lott's standard practice. After Ayres and Donohue showed that his data contained significant coding errors, Lott did not admit to the errors or correct them, but he did switch to citing Olson and Maltz's research in his pieces. Now that Maltz has rebuked him for his misrepresentation of Maltz's work, Lott does not admit to do anything wrong but modifies his claim so that it is so vague that it is difficult to refute.