The Inaccuracy of National Crime Victimization Survey Research

The Inaccuracy of National Crime Victimization Survey Research

However consistent the evidence may be concerning the effectiveness of armed victim resistance, there are some who minimize its significance by insisting that it is rare.[15] This assertion is invariably based entirely on a single source of information, the National Crime Victimization Survey (NCVS).

Data from the NCVS imply that each year there are only about 68,000 defensive uses of guns in connection with assaults and robberies,[16] or about 80,000 to 82,000 if one adds in uses linked with household burglaries.[17] These figures are less than one ninth of the estimates implied by the results of at least thirteen other surveys, summarized in Table 1, most of which have been previously reported.[18] The NCVS estimates imply that about 0.09 of 1% of U.S. households experience a defensive gun use (DGU) in any one year, compared to the Mauser survey's estimate of 3.79% of households over a five year period, or about 0.76% in any one year, assuming an even distribution over the five year period, and no repeat uses.[19]

The strongest evidence that a measurement is inaccurate is that it is inconsistent with many other independent measurements or observations of the same phenomenon; indeed, some would argue that this is ultimately the only way of knowing that a measurement is wrong. Therefore, one might suppose that the gross inconsistency of the NCVS-based estimates with all other known estimates, each derived from sources with no known flaws even remotely substantial enough to account for nine-to-one, or more, discrepancies, would be sufficient to persuade any serious scholar that the NCVS estimates are unreliable.

Apparently it is not, since the Bureau of J...

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...ndgun owners or just those who owned handguns for protection purposes.[36] This procedure was apparently based on the dubious assumption that people who used a gun defensively no longer owned the gun by the time of the survey, or that the gun belonged to someone else, or that the R owned the gun for a reason other than protection or kept it outside the home.

Most importantly, the surveys did not ask enough questions to establish exactly what was done with the guns in reported defensive use incidents. At best, some of the surveys only established whether the gun was fired. The lack of such detail raises the possibility that the guns were not actually "used" in any meaningful way. Instead, Rs might be remembering occasions on which they merely carried a gun for protection "just in case" or investigated a suspicious noise in their backyard, only to find nothing.