Re: Debunking John Lott (was: Re: GUNS: Why here?)

From: Michael S. Lorrey (retroman@turbont.net)
Date: Mon Sep 25 2000 - 15:16:46 MDT


Joe Dees wrote:
>
> >Date: Mon, 25 Sep 2000 10:30:53 -0400
> >From: "Michael S. Lorrey" <retroman@turbont.net>
> >
> John Lott and his book MORE GUNS, LESS CRIME has become, for the progun faction, the garlic they wave in the face of the dreaded gun control vampires, as if its flawless perfection would exorcise all demons of competing views of safety and security. Not so. Many flaws in methodology and various and sundry unwarranted assumptions and unconfirmed (and unlikely) cause attributions plague the work.
>
> To get an academic view of the work of this Bernard nathanson of the progun lobby, I post the critique of it found on:
>
> http://www.handguncontrol.org/research/progun/lott.asp
>
> In 1996, John R. Lott, an Olin Fellow at the University of Chicago School of Law, and David B. Mustard published a
> controversial study which purportedly showed that states that loosened their carry concealed weapons (CCW) laws experienced a
> reduction in certain types of crime specifically because they made it easier for citizens to carry concealed weapons. In 1998, Lott
> published More Guns, Less Crime, a book based on his 1996 study.
>
> It is important to note before detailing the major points of criticisms of Lott's book and study that he is unabashedly libertarian and
> may not be an unbiased source for research on gun-related issues. He has long been a proponent of the "Chicago School" theories
> of law and economics on subjects ranging from crime to the environment. In the past, he has argued that the benefit of a crime to a
> criminal can outweigh the harm that a crime inflicts on a society and, according to him, "the worst thing people can expect from
> dioxin is a bad rash." Two days after the Jonesboro schoolyard shootings, Lott called for arming teachers as the solution to
> preventing such tragedies. Most recently, Lott has argued that the hiring of more women and minorities in law enforcement has
> actually increased crime rates.

Ah, the art of character assassination and ad hominem is never too low for these
people to stoop to. The Olin Foundation (and John Lott) has been continuously
smeared by anti-gunners since Lott's book came out, trying to claim that the
Olin Foundation is in some way controlled by Olin Corp, which they allege is a
gun manufacturer. Even Charlie Schumer has tried to use this smear tactic in a
letter to the Wall Street Journal. His letter (and the Olin Foundation's
rebuttal) are here:
http://www.guncite.com/gcgvschu.html

The 'Chicago School' of economics has been greatly supported by the Olin
Foundation, as its goals are the support of scholarship in free enterprise.

>
> Both Lott's book and his study have been reviewed by academics from a wide range of disciplines from criminology to public
> health. Many of these scholars found serious, fundamental flaws in Lott's methodology and found his claims to be unsubstantiated.
> These researchers include Jens Ludwig at Georgetown University; Daniel Black of the University of Kentucky and Daniel Nagin at
> Carnegie Mellon University; Stephen Teret, Jon Vernick and Daniel Webster, all of Johns Hopkins University; Arthur Kellermann
> at Emory University; and Douglas Weil at the Center to Prevent Handgun Violence.

Try these responses:
http://shell9.ba.best.com/~ddfr/Lott_v_Teret/Response_to_Webster.html

Moreover, there is a newer paper by Plassmann of SUNY Binghamton and Tideman of
Virginia Tech, using other statistical methods which show an even stronger
correlation than Lott indicated in his and Mustard's study:
http://bingweb.binghamton.edu/~fplass/gun.pdf

"John Lott and David Mustard have argued that their county level weighted
least-squares analysis shows that the right to carry concealed handguns has a
statistically significant deterrent effect on crime. However since the number of
crimes committed in a county in a year is a non-negative integer that is zero or
one in most cases for some important crimes, the estimates of an analysis that
assumes a normal distribution are unreliable. In a weighted least-squares
analysis the conclusions of Lott and Mustard with respect to murders vanish when
some plausible changes are made in the specification that is estimated. However,
when the data are analyzed as the produce of a generalised Poisson process, the
average effect of shall-issue laws on the number of murders is even stronger
than Lott and Mustard estimated, and the effect is estimated with much greater
precision...We estimate that right-to-carry laws reduce murders by 11 percent,
which is about 1 1/2 times as large as the effect estimated by Lott and
Mustard."

>
> Unfortunately, while flaws in his research have been widely documented in scientific literature -- and his findings dismissed by
> numerous, prominent researchers -- the gun lobby has successfully used Dr. Lott's flawed conclusions to persuade several state
> legislatures to loosen CCW restrictions in the mid-90's.
>
> Now, after several years in which the nation as a whole has enjoyed a declining crime rate, there is direct evidence that Lott's
> conclusions are wrong. A 1999 analysis of crime statistics conducted by the Center to Prevent Handgun Violence (CPHV)
> demonstrates that allowing people to carry concealed handguns does not mean less crime. The Center found that, as a group,
> states that rely on permissive concealed weapons laws as a crime fighting strategy had a significantly smaller drop in crime than
> states which looked to other means to combat crime rather than make it easier to obtain a concealed weapons permit.

snip
>
> If allowing more people to carry handguns is supposed to be such an effective crime fighting strategy, why did the crime rate go up
> in so many "shall issue" states -- particularly when compared to states that employed other strategies to fight crime? The simple
> answer: allowing thousands of ill-trained citizens to carry guns everywhere they go has no positive effect on the crime rate.
> Research now substantiates what common sense has always argued: in a society riddled with gun-related crime, reducing the
> opportunities where guns can be used will actually reduce the rate of gun violence.

Actually, the reason is because those states with lax CCW laws already had very
low crime rates as a result of their longstanding lax CCW laws. For example,
take Vermont, where you don't even need a permit to carry a concealed weapon.
Total homicides in Vermont annually are typically ten times less than that of
large cities with populations similar to Vermont in its entirety. When standard
statistical variation in homicides occurs, from 15 to 17 murders, thats an
increase of more than 12%, but is well within the bounds of statistical
variation.

Crime in lax CCW states is so low already that the total quantity of deaths the
'increases' the CPHV touts is far less than the total quantity of deaths in
'decreases' in only a few of the tight CCW states. For example, take a city like
Chicago, or DC, a variation in gun deaths of 20% counts for easily 100 lives,
while hundreds more are still dying every year.

The statistical variability in death rates increase, on a percentage basis as
your rate drops closer to the 'noise' level of the statistical sample. What
anti-gunners are mistaking that they are mistaking noise for signal. They abuse
Zeno's Paradox to misrepresent their case.

Moreover, here is his own response to Black and Nagin:
http://shell9.ba.best.com/~ddfr/Lott_v_Teret/Lott_v_HCI.htm

>
> The following Q&A details other major points of criticism of Lott's book and study:
>
> Q: What are the indications that Lott's study of changes in concealed carry laws is flawed?
>
> A: Apart from the obvious mistakes (e.g., Lott's inability to accurately identify when states changed their carry laws), several researchers have shown that small changes in the statistical models Lott uses to reach his conclusions result in large changes in his findings - an important indication that his research is fundamentally flawed. Researchers who have reanalyzed Lott's data, for example, found no beneficial impact from changes in carry laws when Florida was not included in the study, or when they restricted their analysis to counties that had populations greater than 100,000 people.

This is a lie, see page 138-140 of Lott's book.

>
> Q: Doesn't Lott implicitly acknowledge that his work is fundamentally flawed because he does not account for other factors which could affect both the crime rate and the decision by state legislators to change carry laws?
>
> A: Yes. On page 153 of More Guns, Less Crime, Lott writes that "The more serious possibility is that some other factor may have caused both the reduction in crime rates and the passage of the law to occur at the same time." And he goes on to write that "For a critic to attack the paper, the correct approach would have been to state what variables were not included in the analysis." Well, this has been done.
>
> Critics of Lott's study have identified a number of factors that affect crime rates, but which Lott failed to address in his research.
> Examples include changes in how the police go about their business (e.g., implementation of community policing, and
> crime-mapping techniques used by some police departments), changes in poverty levels, gang activity, maturation of the drug
> market, and other changes in gun laws.
>
> Most important, in a paper published in the Journal of Legal Studies (January 1998), Dan Black and Daniel Nagin used a well
> known, formal statistical test that proved that Lott failed to include a number of important variables in his study. On the basis of this
> and other findings, Drs. Black and Nagin, along with Professor Jens Ludwig, concluded that "there is absolutely no credible
> evidence to support the idea that permissive concealed-carry laws reduce violent crime," and that "it would be a mistake to
> formulate policy based on the findings from Dr. Lott's study."
>
> To this day, John Lott has failed to provide any statistical evidence of his own that counters Black and Nagin's finding that Lott's
> conclusions are inappropriately attributed to changes in concealed carry laws. Until Lott can do this, it is inappropriate for him to
> continue to claim that allowing more people to carry concealed handguns causes a drop in violent crime.

Actually, here is his response:
http://shell9.ba.best.com/~ddfr/Lott_v_Teret/Lott_v_HCI.htm

>
> Q: Is it true that John Lott's findings have been dismissed by Florida State University criminologist Gary Kleck, who
> is cited as an authority on gun violence research by Lott and whose work is routinely praised by the NRA?
>
> A: Yes. Kleck has accepted the Black and Nagin critique, writing in his new book that Lott's thesis "could be challenged, in light
> of how modest the intervention was. [More] likely, the declines in crime, coinciding with relaxation of carry laws were largely
> attributable to other factors not controlled for in the Lott and Mustard analysis" (Targeting Guns; p. 372).

Lott responds:"read Kleck's blurb on the dust jacket of my book. He makes a
similar point in the part that they fail to quote in the book. I have asked
Kleck and he can't think of what I may have left out."

>
> Q: John Lott claims that changing the law to allow more people to carry concealed handguns causes a fall in violent
> crime, yet he finds virtually no beneficial effect from changes in handgun carry laws on robbery - the crime most likely
> to occur between strangers, and in public spaces. Is this finding consistent with his theory -- does it make sense?
>
> A: No, it does not make sense. In fact, the finding that changes in concealed carry laws result in a large drop in rape - a crime most often committed within homes by someone who is known to the victim - while showing virtually no beneficial impact on
 robbery is another indication that Lott's study is fundamentally flawed.

His response: See page 133 of the book.

>
> In scientific terminology, the basic criticism made of Lott's research is that the statistical model he used to reach his conclusions is "misspecified." This means, in part, that he did not adequately account for other factors which have an impact on crime rates - and which provide an alternate explanations for his findings. When a statistical model is misspecified, it cannot be used as the basis from which to draw conclusions about the impact of policy decisions. One clue that a model is misspecified is if it produces implausible findings.

Incorrect. Our own David Friedman has a paper here critiquing Black and Nagin's
critique of Lott:
http://shell9.ba.best.com/~ddfr/Lott_v_Teret/Friedman_on_B_and_N.html

And another debunking Teret's critique of Lott:
http://shell9.ba.best.com/~ddfr/Lott_v_Teret/Response_to_Teret.html

David goes on to say about Lott's critics to say:
"This is really the second round of the battle over statistics between
economists and sociologists, criminologist's, et. al., the first being fought
over Isaac Ehrlich's
work on the effect of the death penalty and more generally over the issue of
deterrence. In each case, if you look at the history of the articles, you find
the same
pattern:

Time A: Statistical work is being done by non-economist non-statisticians,
typically criminologist's, sociologists, physicians etc., and is relatively
primitive--on the
order of comparing average murder rates in all states with the death penalty to
average murder rates in all states without, or selecting a small sample of
counties,
without offering any basis for choosing those instead of others, and reporting
what happened in those counties after a shall issue law was adopted, without
controlling for any other variables. The results of this work--that the death
penalty does not deter and that laws permitting concealed carry increase the
murder
rate--are routinely reported as scientific facts by people in the field.

Time B: An economist (Ehrlich, Lott) does a study an order of magnitude more
sophisticated, using both time series and longitudinal data, controlling for
relevant
factors insofar as data is available, using techniques such as second stage
least squares to try to control for problems with unobservable variables, etc.
It produces a
result that the people in the field don't like.

Time C: People in the field publish furious attacks on the economist and on his
study; the latter, insofar as they are legitimate, are arguments showing that
there are
possible explanations for his results other than the one he gave--which is
almost always true, to some degree, of statistical results. These attacks apply
a standard of
proof enormously higher than that applied to the Time A studies--which the same
people happily accepted."

David's father, Nobel Laureate Milton Friedman, on John Lott's research:

        "This sophisticated analysis yields a well established conclusion that
supports the wisdom of the Second Amendment to the United States Constitution
rather than of those who would limit the right of law-abiding citizens to own
and carry guns. . . . Lott has done us all a service by his thorough, thoughtful
scholarly approach to a highly controversial issue."

Now, Guncite states that according to FBI stats, while violent crime in shall
issue states is 8% lower than may-issue states, homicide rates in may issue
states are 13.4% lower than shall
issue.(http://www.guncite.com/gun_control_rtcstates.html)

This is rather obvious, though, because homicides do not equate to murders or
manslaughters. At least half of gun related homicides are, in fact, suicides.



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