In his 6/9/03 posting, Lott claims that Donohue has made a "large number of easily identifiable mistakes". Even if true, such mistakes pale into insignificance compared with the coding errors that Lott made but will not admit to, but let's examine Lott's claims and see how many mistakes he has successfully identified:
he implies that David Olson's paper was so flawed that Olson and Maltz had to withdraw the paper.
Lott has correctly identified a slip up by Donohue, since the paper has not been withdrawn. I checked with Donohue and he informs me that what he should have said was
one author of the other paper (as Lott well knows) has repudiated the paper after concluding that the data on which it (and Lott's work) was based is unreliable.
Maltz's own letter on the subject is here.
Lott continues:
claiming that David Mustard and I "never acknowledge" the costs of guns or the possible bad effects of concealed handgun laws,
Actually, Ayres and Donohue wrote:
they never acknowledge cases on the other side of the ledger where the presence of guns almost certainly led to killings.[12]
This is a reference to the Hattori case, which is a mistake that they acknowledged and corrected in their reply. This mistake is only in their paper because Lott insisted that they not be allowed to correct it. Lott has tried to score points off this mistake three times now---in the reply to their paper, in his AEI talk and on his blog.
Lott continues:
juxtaposing quotes to make it possibly appear that I was arguing about law-abiding citizens carrying guns on planes when the op-ed was about pilots carrying guns (p. 1199)
Actually, the op-ed was also about having off-duty police on planes carry guns and responsible citizens off planes carry guns. I did not get the sense from their quotes that Lott was arguing for law-abiding citizens to carry guns on planes.
that previous work did not deal with the possible impact that cocaine could explain the changes in crime rates attributed to concealed handgun laws,
In fact, they argue that Lott does not adequately control for the impact of crack cocaine, not that he does not try to control for it.
the measurement error problems in county level data
Ayres and Donohue deal with this charge quite thoroughly in their reply:
48. Following Michael Maltz, we have been concerned about relying on any analysis that uses county crime data, particularly if the data extends across the period before and after 1993 (when the reporting agency substantially changed its data collection method). See id. at 1260. But PW claim that we have misread Maltz, and that Maltz did not assert that reliance on the county dataset was unwise. Both claims are false. Indeed, we showed our statement and the PW response to Michael Maltz, and he rejected the PW allegation. Maltz said that, if anything, our paper actually understated the Maltz and Targonski criticism of the county-level data: They view the county data to be severely flawed overall, "especially if" (not "only if") one extends the data across the break in the series that occurred in 1994. Email from Michael Maltz to John Donohue, supra note 13. In response to PW's claim that the measurement problems are no worse in the county data than in the state data, Maltz replies: "[B]oth state- and county-level data are affected, but state-level data are affected much less profoundly." Id.PW also contend that Maltz and Targonski have no discussion of a post-1992 break in the quality of data. Plassmann & Whitley, supra note 13, at 1363. Maltz again disagrees:
We noted:The 1994 NACJD codebook (ICPSR dataset 6669) explicitly notes this in a major heading, "Break in Series," and describes the new imputation procedure it began using in 1994. It goes on to state,These changes will result in a break in series from previous UCR county-level files. Consequently data from earlier year files should not be compared to data from 1994 and subsequent years because changes in procedures used to adjust for incomplete reporting at the ORI or jurisdiction level may be expected to have an impact on aggregates for counties in which some ORIs have not reported for all 12 months.Email from Michael Maltz to John Donohue, supra note 13. "In other words," Maltz continues, "Lott refuses to acknowledge that his entire county-level analysis in the second edition of his book is faulty." Id. In response to the PW statement---"[n]or do Maltz and Targonski provide any evidence that state-level data are more dependable than county-level data," Plassmann & Whitley, supra note 13, at 1363—Maltz replies: "We do so in our response to his response to our paper." Email from Michael Maltz to John Donohue, supra note 13. At the least it must be conceded that there is no truth to the PW claim that we misinterpreted Maltz's views.
Lott continues:
even Philadelphia's concealed handgun laws are incorrectly described
In fact, in Confirming "More Guns, Less Crime", even Lott doesn't dispute that Philadelphia changed to "shall-issue" some years after the rest of the state. He just argues that while it was still "may-issue", they became more liberal about granting permits.
So, to summarize: Lott has only successfully identified two mistakes, one by Donohue in a letter where he wrote "withdrawn" instead of "repudiated", and one in Ayres and Donohue's paper that was only present because Lott insisted on its inclusion. Both of these mistakes have been acknowledged and corrected.
Lott's track record on mistakes is not so good. I could go through a very long list, but I want to focus on the most important ones ones---the coding errors in the data for Confirming "More Guns, Less Crime". Will Lott acknowledge and correct these errors?