FEB 99 UPDATE ON
ANTI-GUN BIAS IN MEDICAL LITERATURE

2/16/99

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At the end of December, 1998, the nejm and gun control advocates used a new and unlikely way to make their points.  This came under the guise of a "book review" by gun control doctor(?) david hemenway in nejm vol. 339 of Dec 31 98 (p 2029).  The "review" was of Professor John R. Lott's book "More Guns, Less Crime:  Understanding Crime and Gun-Control Laws"  In the review, hemenway misrepresented the analyses that were the bases for the book, and misrepresented criticisms (by others) of those analyses.  He said:

In at least six articles published elsewhere, 10 academics found enough serious flaws in Lott's analysis to discount his findings completely.

Note that hemenway didn't specify the articles or the 10 "academics."  This is a typical gun controller tactic designed to make it impossible to rebut.  Note, too, that it covers up the facts that: the "academics" are generally very active gun control ADVOCATES, are very tiny in number in comparison to all those who have reviewed Lott's works, and are mostly "academics" in fields (chiefly medicine) that do not qualify them to evaluate criminological work such as Lott's.  Had hemenway actually read the book he was supposedly reviewing, he would have known that the few criticisms that surfaced about the analyses Lott and Mustard initially reported were dealt with by Lott, with the results communicated to the people who had criticized.  He also explained it all in the book.  The articles were often in newspapers, so as to affect the public perception rather than promote scientific analysis.  Lott reran his analyses with changes to accommodate the criticisms people made, and found that the changes made little difference in results.  In fact, they sometimes re-inforced his earlier conclusions!

Many of the criticisms were in the news the day the story about the Lott-Mustard work hit the news, or very shortly thereafter.  Reading the part of Lott's book that deals with the criticism is highly instructive about the tactics of gun control advocates.  The book is cheap and would be a "must read" at ten times the price.

One thing that people should realize about hemenway's statement is that:  1)scientists pursuing truth publish descriptions of their studies and experiments; 2)other qualified scientists review the studies/experiments, try to replicate the original ones, and question or point out possible deficiencies; 3)the original scientists respond; and, 4)they all perform and report upon analyses, studies or experiments to clear up disagreements or questions.  In science, the original criticisms (if any) are not proof that the original work was not valid.  In science, the criticisms are sent directly to the original researchers or are released through professional journals, not the "news" media.

Back to hemenway's statements:  In the very next paragraph, hemenway said the central problem of Lott's analyses is that they don't "include variables that can explain [crime] cycles."  The truth is that the frequencies of different kinds of crime are the results of a large number of things, some of which may not even be recognized yet.  Some of these things promote crime, others deter it.  The "cycles" observed in crime rates result from all these things acting together.  It will not be possible to explain every bit of crime rates until we identify all the things that cause or deter crime, determine good ways to measure those things, then actually measure them.

But the statistical methods Lott and Mustard use are able to determine how much of crime rates (and other rates, such as accident rates) is explained by WHATEVER FACTORS ARE CONSIDERED (or other things correlated with those factors).  The methods do not depend upon being able to explain the effects of any other factors.  The only way the conclusions about a considered factor can be incorrect as a result of an unconsidered factor is if there is a high degree of correlation between the two factors.

Hemenway cited as examples of things not taken into consideration:  "gangs, drug consumption, or community policing."  No matter what Lott and Mustard took into account anyone with any sense could come up with a list of things that weren't considered.  Hemenway simply hopes to discredit by picking at the work.  Hemenway knows that there are no existing data about the extent to which any of his suggested factors applies across the nation.

If there were such data, Lott would already have used it because he only cares about finding solutions to crime and violence problems, and because data is easily added in with the rest of the data in his processing system to account for any new measures he wants to check.  Lott has been anxious to take into account any factor anyone seriously suggests as relating to any type of crime—provided only that there is some measure of the factor available for a significant part of the country.  The only shortcomings of Lott's works are that data is limited and the statistical methods are beyond the immediate understanding of people without statistical methods knowledge.

Saying that "many of Lott's findings make no sense," hemenway then misrepresented results of Lott's work by claiming that Lott found that lower income and higher unemployment increases rates of violent crime, and that "reducing the number of black women 40 years old or older … substantially reduces murder rates.  Indeed, according to Lott's results, getting rid of older black women will lead to a more dramatic reduction in homicide rates than increasing arrest rates or enacting shall-issue laws."

We haven't been able to find where the claim about income and unemployment came from, but the thing about black women came from an article by Jens Ludwig, one of the few criminologists inexperienced enough to be anti-gun, in the Spring '97 (vol 367) issue of the Valparaiso U. Law Review.  The statement is parroted by hemenway in hopes of making "black" people and people concerned about racial discrimination think that Lott's work blames blacks for murder.  Let's look at Ludwig's statement:

"Perhaps even more surprising are the coefficient estimates for measures of a county's population that is black, female, and between the ages of 40 and 49 or over the age of 65.  [Lott and Mustard find] evidence to suggest that these variables have a statistically significant, positive correlation with murder rates … There remain two competing explanations for [these] findings.  First, middle-aged and elderly African-American women could be actively [engaged] in the commission of … murders across the United States.  The more likely explanation is that [Lott-Mustard results] are misspecified and, as a result, their coefficient estimates are biased."

Note that Ludwig said the population of black women in their forties has a "statistically significant … correlation."  Had there been more than a weak correlation, he would have said so.

Had hemenway actually read the book he was "reviewing," he would have known that Lott addressed the claim, along with Ludwig's additional claim about aggravated assault rates, in the book (p143, No.11)  Lott pointed out that there was a third alternative although young Ludwig thought there were only two.  That third alternative is that high rates of some particular type of crime can be associated with existence of some demographic group because that group is more prone to be the victims of that type of crime.  For example, almost all rape occurs where there are young women.  It is well established that numerous categories of crime, including murder, are committed by blacks at a higher per-capita rate than by whites and that blacks are also victimized by these crimes at a higher per-capita rate than are whites.

A thing that Lott didn't mention is that Ludwig has to be exceedingly unqualified or dishonest to have made the assertion.  Another is that there is yet another (fourth) possibility.  The fact is that the male population that is black and is from late teen-age up to about 30 years old commit various crimes (including murder) more than other parts of the overall population (on a per-capita basis).  Where there are male blacks from 16 to 30 years old, there are black mothers from about 33 to about 55 years old.  Since there is correlation between crime and young, black males, there is obviously correlation with their mothers.  Had those women not existed 16 to 30 years earlier, those young criminals and their crimes would not have existed during the period covered by the Lott-Mustard work.

There is no doubt that not having any minority populations would have a greater impact on crime rates than the impacts of increased arrest rates and enacting shall-issue laws.  Yet, thankfully, nobody is blaming blacks, or any other population (other than criminals), as a group.  Experienced criminologists say that working to fix the problems that plague inner city residents and other poor in our country will be infinitely more beneficial in reducing crime than enacting more useless and counterproductive gun controls.  In fact, allowing and helping law-abiding minority people to defend themselves would go a long way toward solving their criminal victimization problems.

Later hemenway criticized the analysis Lott did, after publication of his paper, regarding the relationship of crime rates to the portion of people who own guns.  He said that the organization that did the polls from which Lott derived the gun ownership data said the data cannot be used as Lott used it, as though one organization is the supreme judge of how others can use information.

He then said the data from the polls indicated that US gun ownership "increased an incredible 50 percent" between 1988 and 1996 "yet all other surveys show either no change or a decrease in the percentage of Americans who personally own firearms."  As we point out in our article about the number of guns we own, the surveys hemenway relies on are worthless.  Lott, on the other hand, found a way to get at the gun ownership rate without having the problem of respondents falsely denying ownership.  He used "exit polls" (taken of voters exiting voting places) so that, even though the pollster and the respondent are face-to-face, the survey is anonymous (since the pollster doesn't ask for any identifying information).

The "review" of Lott's book is wound up by criticizing Lott for making his results public and providing them to policy makers.  This is extreme hypocrisy!  Gun controllers get full cooperation and even active participation from the media regarding any stupid thing they want to say, and press politicians at all levels of government.

Why would someone with some sense and integrity supposedly reviewing a book write things that look as though the person could not really have read the book?  It is not clear whether hemi has no sense or has no integrity.  It must be one or the other or both.  A person with integrity would not write a book review without having actually read the book.  Maybe he just couldn't understand it.  He did say in the review that "some training in econometrics is essential to assess his statistical approach" (as though he has the training?).  Maybe the bias is only because hemi is paid to promote gun control.

In contrast to the "review" of Lott's book, hemenway's "review" of a book by a gun controller actually stated a number of false things as fact rather than just telling what the author said.  This book is based on observations of gun advertising.  Hemi characterized features that would aid in shooting accurately and in stopping violent attackers as having "Rambo appeal."  He erroneously indicated that grenade launchers are "offered" and that "Chinese AK-47s and Russian SKS assault rifles" are being sold in the U.S.  If so, where?  And, why are the federal laws not being inforced?

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