From: [t--u] at [eclectic.ss.uci.edu] (Tim Lau)
Newsgroups: talk.politics.guns
Subject: Chicago CCW Study - Rebuttal
Date: 4 Sep 1996 16:58:32 -0700
Organization: Andreas Klemm, 41469 Neuss, Germany
Hey guys, I just got this in the mail. I am in no way supporting it,
and most of the argument is unsubstantiated and pretty weak. However,
I am not versed in statistics, so I can't comment on the "incorrect
and discredited methodology" part, but that's what you guys are for!
Here it is:
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August 8, 1996
Critical Commentary on a Paper by Lott and Mustard
by Stephen Teret
The Johns Hopkins Center for Gun Policy and Research
Laws that help determine wheter people carry concealed weapons may affect
the incidence of gun deaths in this country. These laws, therefore,
deserve the most careful and scientifically accurate evaluation. The Johns
Hopkins Center for Gun Policy and Research and its affiliated experts have
carefully reviewed the paper by John R. Lott, Jr. and David B. Mustard
on the impact of "shall issue" laws, which require officials to issue
permits to carry concealed firearms. We find the authors'
clams that such laws deter violent crimes to be unsubstantiated. Their
study contains factual and methodological flaws, and reaches conclusions
that are implausible based on criminologic research and theory. Some of the
most important problems with Lott and Mustard's study are outlined below.
The study uses incorrect and discredited methodology. The results of any study
are influenced by the type of statistical techniques used by the
researchers. The technique used in most of Lott and Mustard's analyses
has been deemed by criminologists and econometricians since the early
1970s to be inappropriate for this type of study. The validity of the
statistical techniques chosen by Lott and Mustard depend on the
assumtion that data used in the study (such as crime rates in neighboring
counties, and crime rates in consecutive years) are not related to each
other. If, however, relationships exist, than false findings of
statistical significance will occur.
Lott and Mustard use arrest rates to predict crime rates, and this too is
problematic. For example, their estimate of the laws' effect on crime
rates varies five-fold, depending on how the deterrent effects of arrest
were measured. A National Academy of Sciences panel of experts determined
nearly two decades ago that arrest and crime rates can not be sufficiently
disentangled to permit analyses such as those used by Lott and Mustard.
The authors demonstrate that "shall issue" laws tend to be implemented
when violent crime has recently increased. The reductions in violent crime
that the authors attribute to the laws may simply be a commonly observed
downward drift in crime rates toward some long-term average level. The
authors failed to use state-of-the-art analytic techniques which would
distinguish a true effect of the law from an expected downward drift towards
average levels.
The study's results depart from well-established criminologic theory and
facts about crime. "Shall issue" laws were adopted principally to deter
predatory street crime, the most common example of which is robbery by
a stranger. But Lott and Mustard's results indicate that "shall issue"
laws had little or no effect on robbery rates. The strongest deterrent
effects estimated were for rape, aggravated assault, and murder. But most
rapes and aggravated assaults are committed by someone known to the
victim - a situation in which carrying a concealed gun in public areas
is less relevant. In addition, only 17% of murders are the result of
predatory crimes.
Lott and Mustard argue that criminals, in response to "shall issue" laws,
are substituting property crim for crimes likely to involve contact with
victims, but the observed "substitutions" make little sense. No credible
criminologic theory can explain why a criminal would steal a car because he
felt deterred from assaulting someone.
The study does not account for the effects of other important gun laws.
In some of the states that passed "shall issue" laws, other gun laws
were also enacted during Lott and Mustard's study period. For example,
between 1989 and 1991; Florida passed a law requiring all handgun
purchasers to undergo a background check and a 3-day waiting period;
Oregon lengthened its waiting period and required more detailed background
checks; and, Virginia adopted an instant background check system for
handgun purchasers (later extended to all firearms). These other laws
may substantially affect homicide and other crime rates, yet Lott and
Mustard fail to consider their effects.
Knowing the exact date each "shall issue" law took effect is critically
important to measuring its impact -- yet the study includes some errors
in these dates. For example, the authors claim that Virginia adoped its
"shall issue" law in 1988. But that law continued to give courts
considerable discretion over when to issue a concealed weapon carrying
permit (and some populous counties issued very few permits). Only in
1995, in a much publicized move, did Virginia elminate that discretion.
Also, the authors assert both that Maine adopted a new "shall issue"
law in 1985, and that Maine nevertheless had a law from 1977-1992. During
the study period, Maine adopted changes to its concealed carry law in
1981, 1983, 1985, 1989, and 1991. The 1985 changes do not eliminate the
rather subjective requirement that permits be issued only to persons
with "good moral character."
The study does not consistently define what it is evaluating. Lott and
Mustard describe a "shall issue" law as one that requires "permit
requests be granted unless the individual has a criminal record or a
history of significant mental illness...." Yet they classify as
"shall issue" some state laws that do not fit this definition. For
example, even the NRA (in its Internet materials) recognizes that
authorities in Connecticut and Alabama retain some discretion over who
gets a concealed weapon permit. This means Lott and Mustard may mix
together states with quite different rules for granting a permit.
For more information contact Professor Stephen Teret, (410)955-3995.
*Established in 1995 with funding from the Joyce Foundation of Chicago,
The Johns Hopkins Center for Gun Policy and Research is dedicated to
reducing gun violence. The Center provides accurate information on
firearm injuries and gun policy; develops, analyzes, and evaluates
strategies to prevent firearm injuries; and conducts public health
and legal research to identify gun policy needs.
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Typos are all mine.
Tim
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Tim Lau <[t--l--u] at [uci.edu]>
Home Page: http://www.w3systems.com/liberty
Public Key: http://www.w3systems.com/pubkey.html
"Those who would give up essential liberty to purchase a little
temporary safety, deserve niether liberty nor safety."
-- Benjamin Franklin
Nov 11 1755, from the Pennsylvania Assembly