There's nothing quite a neat as a circle, is there?
Kleck deliberately presents fatally flawed data because he has an agenda. Why does he have that agenda? I don't know, but it's perfectly clear he has one.
So, in other words:
- We know Kleck was pursuing an agenda because he used flawed data from his survey.
- We know the data was flawed because Kleck influenced the survey.
- We know Kleck influenced the survey because he was pursuing an agenda.
No matter where in the circle you start, the conclusion is the same as the premise;
circulus in demonstrando (
http://fallacyfiles.org/begquest.html)
My guess is that he wanted to sell books.
Except that "Armed Resistance to Crime: the Prevalence and Nature of Self-Defense with a Gun" was published in the
Journal of Criminal Law and Criminology, and journals don't pay researchers for submitted articles.
As gejohnston pointed out, academics don't make a lot of money on royalties either, and one's academic career isn't enhanced by having higher sales numbers.
A shorter, and more honest, version of your circular argument is:
- I don't like his results, he must have rigged the data
- He must have rigged the data because I don't like his results
There just isn't a reliable method for estimating DGU's
Yes, particularly using survey data. Or so Philip Cook and Jens Ludwig argued, as did Hemenway himself with Deborah Azrael, while trying to explain why their own DGU surveys, to their dismay, produced results consistent with Kleck's (1.5m and 900,000 DGUs annually, resp. which due to smaller sample sizes had margins of error that readily overlapped Kleck's). The term for that is "ad hoc fallacy" (
http://www.infidels.org/library/modern/mathew/logic.html#adhoc) and it's particularly egregious in the case of Cook & Ludwig, who were happy to accept findings from their survey that
were to their liking (e.g. indicating that ~35%, rather than 50%, of American households possessed firearms).
You could have two wackjob idiots brandishing guns at eachother over a parking space, and both could report that incident to Kleck as a DGU.
From Kleck & Gertz's original study:
Cases of "mutual combat," where it would be hard to tell who is the aggressor or where both parties are aggressors, would be a subset of the 30% of cases where assault was the crime involved. However, only 19% of all DGU cases involved only assault and no other crime where victim and offender could be more easily distinguished. Further, only 11% of all DGU cases involved only assault and a male defender--we had no information on gender of offenders--some subset of these could have been male-on-male fights. Thus, very few of these cases fit the classic mutual combat model of a fight between two males. This is not to say that such crimes where a gun-using combatant might claim that his use was defensive are rare, but rather that few of them are in this sample.
As Kleck notes in his rebuttal, "We addressed this latter possibility in our article and showed that it could not account for more than a small fraction (probably less than a tenth) of the incidents we counted as DGUs.<18> H does not rebut that evidence."
Another problem with self-reporting is that gun owners see a DGU as a heroic incident, leading to a tendency to over-report.
As Kleck & Gertz point out, most of their respondents who reported a DGU had, as a result, to cop to some form of unlawful behavior in so doing, usually carrying concealed without a permit (which were markedly more rare in 1992 than they are now), which hardly seems "socially desirable." Moreover, as Kleck & Gertz also point out, if so many of their respondents were engaged in "false portrayals of heroism," remarkably few of them provided tales of derring-do, reporting the assailant had a firearm in only 17.9% of cases, and was completely unarmed in 51.9% of cases. Similarly, when asked how likely they considered the possibility that someone would have died had they not used a firearm for protection (in effect, whether they saved their own or someone else's life), the combined number of respondents who replied "probably" or "almost certainly" came in at slightly less than 30%. That seems remarkably low for manufactured tales of heroism; surely we consider it more "socially desirable" and (thus) heroic to use a firearm to protect life than to protect a wallet or a VCR.
The pollsters asked to speak to male heads of households, deliberately excluding females in the home. <...> They also oversampled the south and midwest.
You're overstating a passage from Hemenway's piece:
Interviewers do not appear to have questioned a random individual at a given telephone number, but rather asked to speak to the male head of the household. <17> If that man was not at home, the caller interviewed the adult who answered the phone. <18> Although this approach is sometimes used in telephone surveys to reduce expense, it does not yield a representative sample of the population.
First off, note the phrase "do not appear." Why the vagueness? Either Hemenway doesn't actually
know what the interviewers asked, or he's trying to make it sound like Kleck & Gertz attempted to obfuscate the fact they oversampled males (which they didn't, see below).
Second, "females in the home" (at least, those over 18, as under-18s
were excluded) were not
excluded. Undersampled, yes, but you can't weight the data if you don't have females in the responses in the first place.
Third, yes, Kleck & Gertz oversampled for males and oversampled the South and West (note: the West, not the Mid-West).
They say so themselves in the original study, and explain why:
To gain a larger raw number of sample DGU cases, we oversampled in the south and west regions, where previous surveys have indicated gun ownership is higher. <45> We also oversampled within contacted households for males, who are more likely to own guns and to be victims of crimes in which victims might use guns defensively. <46> Data were later weighted to adjust for oversampling.
Oversampling is nothing unusual in surveys (Hemenway's insinuation that it is notwithstanding), and is commonly done to develop a more accurate picture of a specific sub-group of the sample. For example, presidential polls conducted in early 2008 routinely oversampled African-Americans to get a better picture of how they felt about Barack Obama. In the case of the Kleck-Gertz study, they deliberately oversampled the sub-groups more likely to have experienced a DGU to gain more data about the circumstances of DGUs, instead of winding up with a large pile of non-DGU responses from which no further information could be gleaned. None of this is an issue provided you weight the data to compensate for oversampling.
Hemenway complains that "the authors do not explain their weighting technique" but in this instance, it's not all that arcane because the survey is fairly straightforward in nature. Weighting can get very tricky in longitudinal studies, in which multiple surveys are conducted in an effort to track changes--particularly in specific sub-groups of the sample--but the Kleck-Gertz survey is a "snapshot" (i.e. a recording of a single moment in time).
They ignored the statistical impact of non-respondents.
Why would non-respondents be skewed one way or another? Kleck & Gertz describe the line of questioning thus:
Each interview began with a few general "throat-clearing" questions about problems facing the R's community and crime. The interviewers then asked the following question: "Within the past five years, have you yourself or another member of your household used a gun, even if it was not fired, for self-protection or for the protection of property at home, work, or elsewhere? Please do not include military service, police work, or work as a security guard."
If a respondent answered "no" to that question, that was, for all practical purposes, it:
the response was counted as "no DGU," whether or not the respondent subsequently went on to complete the full list of questions (minus "those pertaining to details of the DGUs"). As Kleck and Gertz (repeatedly) point out, it was significantly easier to give a response that would
not be counted as a DGU than to give one that
would.
So again, why would non-responses have been disproportionately likely to have been non-DGUs? This is a question that demands an answer before it can even be accepted that non-responses even had a statistical impact. You'd have to assume that the interviewers stated in their opening patter, even before the "throat-clearing" questions, that the purpose of the survey was to collect info on DGUs, thereby encouraging non-responses from persons who hadn't experienced one; there would, however, be a few problems with such an assumption.
First, there's no evidence for it. And by "evidence," I mean evidence, not some "it stands to reason that they must have" circular argument.
Second, 95.5% (4,755 out of 4,977) of the raw (i.e. unweighted) responses were counted as "no DGU." If the interviewers' wording had been intended to actively discourage non-DGU respondents, why would the raw sample data end up containing over 95% "non-DGU" responses?
So, to conclude, the aspersions you cast on Kleck & Gertz's survey are based to a large extent on circular arguments and outright fabrication. If the flaws in Kleck & Gertz's work were really all that glaring, why is Hemenway (who has a pretty obvious anti-gun agenda) one of the few people to point them out? Why did Marvin Wolfgang (described by the
British Journal of Criminology as "the most influential criminologist in the English-speaking world") in his piece "Tribute to a View I Have Opposed" (originally published in the Fall 1995 issue of the
Journal of Criminal Law and Criminology, reprinted here:
http://www.saf.org/LawReviews/Wolfgang1.html ) state:
I am as strong a gun-control advocate as can be found among the criminologists in this country. If I were Mustapha Mond of Brave New World, I would eliminate all guns from the civilian population and maybe even from the police. I hate guns--ugly, nasty instruments designed to kill people.
<...>
What troubles me is the article by Gary Kleck and Marc Gertz. The reason I am troubled is that they have provided an almost clear-cut case of methodologically sound research in support of something I have theoretically opposed for years, namely, the use of a gun in defense against a criminal perpetrator. Maybe Franklin Zimring and Philip Cook can help me find fault with the Kleck and Gertz research, but for now, I have to admit my admiration for the care and caution expressed in this article and this research.
Can it be true that about two million instances occur each year in which a gun was used as a defensive measure against crime? It is hard to believe. Yet, it is hard to challenge the data collected. We do not have contrary evidence.
<...>
The Kleck and Gertz study impresses me for the caution the authors exercise and the elaborate nuances they examine methodologically. I do not like their conclusions that having a gun can be useful, but I cannot fault their methodology. They have tried earnestly to meet all objections in advance and have done exceedingly well.
It seems exceedingly hard to credit that a respected criminologist, and one with an intense dislike of firearms to boot, would not only fail to pick out such glaring flaws in Kleck & Gertz's work, but actively praise them for the soundness of their methodology.
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