Yes, the measure of shooting DGUs is inaccurate because of the small
number (16) of sample cases. A 95% confidence interval is 100,000
to 300,000 criminals are shot by armed citizens each year.
However, even allowing for the inaccuracy, the number does not seem
possible.
Eugene Volokh writes:
(2) Could it be that this figure is not that far off the mark
considering that a number of career criminal-career criminal
confrontations may accurately be called "defensive gun use"?
Criminals, after all, sometimes have to defend themselves, too, and
they might be quite honest when they say they were acting (in that
situation) defensively. Of course, some might be less thrilled by
those DGUs than by "honest citizen" DGUs; but the same overestimate
may take place in the NCVS --- it may be that many of the robberies
and assaults counted by the NCVS, for instance, are basically bad guys
robbing/assaulting bad guys. Am I missing something?
This does not seem likely. The number is greater than the NEISS
estimate of all shootings (criminal, justified, suicidal and
accidental). Kleck has used an estimate of a 15% fatality rate from
defensive shootings. 200,000 such shootings would therefore result in
30,000 shooting deaths from self-defense shootings, which is much more
than the total for all gun homicides, criminal or lawful.
(3) Finally, one thing that does make me doubt that the
respondents were lying is that --- as Kleck points out --- the great
majority of the reports did not involve the gun being fired. Why
would someone lie in this sort of survey? Presumably, I'd guess, to
make themselves seem macho to the interviewer (pointless, of course,
but possible).
Some may believe that it is a citizen's duty to fight back against
crime, just as it is to vote. I believe that surveys tend to
overstate the number that vote by a few percent.
But if so, why would a lot of the liars invent such
humdrum incidents?This seems to be buttressed by the other details; in most cases,
the offender was said to be unarmed; in very many, there was no
threat or attack by the offender; in 47% of the cases there was only
one offender. Again, not very macho stuff.
It may be that they are describing real DGUs but changing some of the
details as in who it happened to and when it happened. There is
support for this in that Kleck found that 85% of the time the gun user
was the respondent rather than someone else in the household. Since
the respondent was randomly chosen from within the household the
correct number should have been 51% (the average household size is
slightly less than 2). Kleck found this surprising and decided that
it was because the respondent was concealing DGUs by other household
members. In table 1 it would appear that he multiplies the
numbers from the other surveys that were household based by 1.7 to
compensate for this under counting.
Alternatively, a respondent making up a DGU, or describing a friend's DGU
as if it happened to someone in the respondent's household will tend
to make him or herself the defensive gun user. It may be that of
those that reported a DGU to Kleck, 70% made it up or changed the user
to him or herself. That would leave 15% where the respondent was the
user and 15% where it was someone else in the household.
There is a similar anomaly with when the incident occured. You would
expect 20% of the DGUs to have occured in any one of the five years.
But twice as many (40%) occured within the last year.