W A Collier writes:
How the NCVS miscounted DGUs
Undersized sample, poor methodology, bias in the questions, unsound methods and procedures in eliminating bias, and unlike Kleck, they started with the conclusion (there are only a small number of gun defenses) as an objective to be proven (not the scientific method) whereas Kleck started with the question (How many DGUs are there) and let the numbers supply the answer, pro or con.
You need to inform yourself better about the NCVS.
- The sample size is about 100 times that of Kleck's survey.
- The NCVS methodology has been refined over 25 years of use and is the benchmark for all other victimaization surveys.
- The questions are not biased (I bet you don't even know what they are.)
- The NCVS does not use unsound methods to eliminate bias. There is extensive documentation on the methods they use. I suggest you consult it.
- The NCVS did not start with a conclusion. The NCVS was designed to measure crime and responses to crime. The DGU estimate is just one of the statistics you can get from it. On the other hand, Kleck was famous for his spirited advocacy of the existence of large numbers of DGUs before he conducted his DGU survey.




