Comment on the Recent Work of Kwon, Scott, Safranski, and Bae: No, Your Evidence Dosen't Prove What You Think It Does!
Kovandzic, Tomislav V., The American Journal of Economics and Sociology
Kwon, Scott, Safranski, and Bae (1997, p. 41) use a cross-sectional research design to assess the effectiveness of gun control laws on firearm related deaths. According to their assessment: "The multivariate statistical regression model suggests that the existence of gun control laws indeed have a deterrent effect on firearm deaths" (p. 41). Although some gun control laws indeed might have a deterrent effect as claimed by Kwon et al., their evidence does not support this conclusion. In fact, the Kwon et al. study suffers from many methodological flaws and this renders any substantive conclusion impossible. Most of what is reported by Kwon et al. can be attributed to methodological artifacts. Furthermore, the authors omit the mention of a large number of published books and articles about the relation between gun control laws and violence.
The authors in this study are simply wrong when they state, "In spite of charged emotional debates and passage of numerous laws and regulations, no empirical studies have been done to evaluate the effectiveness of gun control laws in this country. The debate on the Brady Bill could have been better informed by scientific research" (p. 41). At the time this article was published in the AJES, there were at least forty-five empirical studies that evaluated the impact of gun laws on violent crime, suicide, and gun accidents, the bulk of which suggest that gun laws have no impact on rates of violence (Kleck 1991, pp. 251-255, 302-303, 390-392; Kleck, 1995).
More specifically, Kleck and Patterson (1993) completed a Study that evaluated the effectiveness of nineteen gun laws at both the state and city level; they found that most gun control restrictions have no net effect on violence rates. Criminologists on both sides of the gun control debate have cited the Kleck and Patterson study widely, demonstrating a technically more sophisticated research methodology.
Kwon et al. compare their results to a study conducted by Mauser and Holmes (1992). They then erroneously inform their readers that the Mauser and Holmes study found a deterrent effect for the 1977 Canadian gun law on homicide rates. In fact, Mauser and Holmes (1992) stated in their conclusion, "The results are consistent with the findings of previous studies that the 1977 Canadian firearms legislation did not have a significant effect on homicide" (p. 613).
Which Gun Laws were Evaluated?
The authors claim to examine the effectiveness of gun control laws prior to the passage of the Brady Bill in 1992. Unfortunately, they do not make clear which laws they attempt to evaluate. Instead the authors state, "The purpose of this study is to investigate the effectiveness of laws and regulations prior to the passage of the Brady Bill in 1992. A multivariate statistical technique is proposed to establish the relationship between the number of gun related deaths by states and sets of determinants including state laws and regulations on firearm use" (p. 42).
This passage suggests that all current state gun law statutes prior to the passage of the Brady Bill in 1992 were to be evaluated. As of 1990 there were at least nineteen different types of gun laws in the United States ranging from gun registration requirements to assault weapon and handgun bans (Kleck and Patterson 1993, p. 262). However, Kwon et al. focus on only three types of gun laws: those requiring (1) background checks, (2) licensing requirements, and (3) mandatory waiting periods.
Tests of Statistical Significance
The most serious problem with this work is the authors' disregard for tests of statistical significance. Kwon et al. state, "According to the model, states with gun control laws had almost 3 fewer deaths per 100,000 than states without any such laws. The relationship, however, is not statistically significant" (p. 46). Kwon et al. may have misunderstood what significance tests mean. …