Sorting Out the Gun Stats
by Ari Armstrong, July 14, 2000
Iain Murray is a bright guy and a good writer, and in his June 18 article in the Denver Post ("Secrets and Lies: Questionable Stats Plague Gun Debate") he goes a long way in discrediting bogus statistics relating to guns. However, in his criticisms Murray addresses only the best arguments of the anti-gun lobby, and only the worst arguments of civil arms advocates. Thus, his analysis falls prey to problems of selective sampling that he as "senior analyst at the Statistical Assessment Service" ought to know to avoid.
Perhaps Murray realized that if he didn't appear to bash both sides with equal vigor, he probably wouldn't be published by a main-stream newspaper like the Post (at least not on the front page of the Perspective section on a Sunday.)
A careful reading of Murray's piece will show more sympathy with the civil arms side. The anti-gun lobby, according to Murray, uses "the most abused statistic" (the claim that 13 children die per day) and the "least reliable statistic" (the allegation that a gun is 43 times more likely to kill a family member than a criminal). Meanwhile, Murray says the claims of civil arms groups regarding the instances of self-defense "might not accurately represent the numbers in the population as a whole." Those numbers "may well be exaggerated."
Thus, Murray levels more severe criticisms against the anti-gun lobby, even though he maintains the superficial appearance of equal disdain. One might be tempted to surmise that Murray cleverly devised his article as a way to infiltrate the anti-gun lobby with good ideas. He makes the customary pejorative use of the term "gun lobby." (I intentionally use the term "anti-gun lobby" as a way to counter the usual bias in the main-stream media, but I'm always very upfront about my use of such terms.) The only place Murray clearly says something bad about gun ownership is when he describes the "'moral hazard' of employing a dangerous weapon for self-protection." He makes this comment despite the overwhelming evidence that nearly all gun owners treat their firearms with extreme safety.
But on to specifics. Murray writes, "Most of those [teens 15-19] are killed because of their involvement in distinctly un-childlike activities, like drug-related crimes." He follows up:
The murder rates suggest strongly that the problem is not nationwide, but concentrated in inner-city minority and Southern white microcultures. It is stupid to deny that guns exacerbate the problem, but whether their stricter control across the board would alleviate it is another matter.
The real problem with violence in America is drug prohibition. Gun prohibition would likely only exacerbate the problems of gang violence. While gun restriction laws would either not affect gang violence or increase it, it's clear that such laws increase criminal victimization.
Of course, this last point is made clear by Yale Professor John Lott, especially in the Second Edition of his More Guns, Less Crime. But Murray never addresses Lott's most substantive claims. Instead, Murray restricts his discussion of Lott to mass public shootings. Murray writes,
[T]he gun lobby [?!] relies heavily on the work of Yale economist John Lott, and often quotes research which appears to show that "concealed carry laws reduce the number of mass public shootings." Lott's work does indeed suggest that, but the problem is that mass public shootings are unbelievably rare.... When there are few cases to analyze, statistics lose much of their usefulness.
Murray's comment is less than fair. It wrongly gives the impression that Lott's work focuses on mass public shootings. However, the section in Lott's book (first edition) covering the phenomenon covers three pages. Three pages out of 165 pages of material (plus additional pages for notes and appendices) constitutes less than 2% of what Lott had to say. Obviously, Murray's criticism does not apply to the vast majority of Lott's figures.
In addition, it's not clear that Murray paid attention to Lott's broad definition of a mass public shooting, which is "one or more people either killed or injured by the shooting" (100).
Clearly, quoting Lott's figures about mass public shootings (even assuming those figures are weak) is better than quoting the 43:1 ratio. Lott's figures, as Murray acknowledges, at least constitute legitimate science, whereas the 43:1 ratio used by the anti-gun lobby is intentionally deceptive and always has been.
It becomes evident that Murray didn't bother to read Lott's work with the following comment in the Post:
[I]f a state passes a law in response to a rare mass public shooting, it is statistically likely that there will appear to be fewer such shootings after the event, because the law of averages says it will be along time before the next one.
However, Lott's work shows an initial, slight increase in such shootings following the passage of concealed handgun laws, followed by a rapid and tremendous decline of such shootings. Oops. In Lott's words,
[A]lthough the total number of deaths and injuries from mass public shootings actually rises slightly immediately after a nondiscretionary concealed-handgun law is implemented, it quickly falls after that, with the rate reaching zero five years after the law is enacted. (100-101)
In the future, Murray might consider reading Lott's book before publicly commenting on it.
Murray has a little more ground to stand on when he criticizes the claim that 2.5 million crimes per year are prevented by armed citizens. He writes,
[S]urveys (conducted by all sides of the gun debate) produce numbers for defensive gun uses ranging from 764,000 to 3.6 million a year. But as some researchers are careful to point out, they suffer from what statisticians call "false positives"... This means that the figures may well be exaggerated. Pro-gun campaigners never point this out.
Murray is right: there might be false positives on these surveys. Perhaps some people just want to play the hero; perhaps some gun owners want to purposely skew the results. However, there is also the possibility of false negatives. If people don't trust the confidentiality of the survey, they may not admit to having used a gun in self-defense, especially in those areas where gun ownership is prohibited by law.
In general, crime statistics aren't very reliable. For instance, the majority of suspected rapes are never reported. Many crimes go unreported, as do many instances of self-defense, merely because the victim doesn't want to suffer the additional burdens of police scrutiny and paperwork. We work with what we've got. Again, there is a big difference between using plausible if uncertain statistics, and using intentionally deceptive claims such as the "13 children" statistic.
While Murray makes some factual and stylistic errors, his piece on the whole contributes to a quality debate. Hopefully members of the anti-gun lobby bothered to read it.