Professor of Criminology, Florida State University
- Of the 90 findings from 41 studies reviewed only four (8%) findings were based on validated measure of gun prevalence used more than five control variables, and correctly used causal order procedures.
- 17% of the findings were methodologically sound and showed a positive and significant correlation between gun ownership and homicide.
- The more methodologically sound the study is, the less likely it supports the hypothesis that more guns is correlated to more crime.
In the article, “The Impact of Gun Ownership Rates on Crime Rates: A Methodological Review of the Evidence,” Kleck examines the relationship between gun ownership and crime, especially violent crimes. Kleck conducted a literary review of 41 studies to determine which studies on this topic are better or worse methodologically and to find a relationship between gun ownership and homicide. Kleck used three criteria to sort the studies: 1) a validated measure of gun prevalence 2) authors controlled for confounding variables, and 3) researchers used suitable causal order procedures. In the 41 studies Kleck reviewed there were 90 unique findings. Kleck found only 28 of findings (31%) were based on valid measures of gun prevalence. Eleven percent of the findings (12%) controlled for more than five confounding variables. Only four findings (8%) met all three conditions of Kleck’s critical analysis and only ten (9%) met two or more of the criteria. The findings of the studies showed that 21 (52%) showed positive and significant associations between gun levels and homicide rates, but when Kleck accounted for the reliability of the studies in his analysis, he found that on 17% of the findings were positive and significant. In conclusion, Kleck noted that the more methodologically sound the study is, the less likely it supports the hypothesis that more guns is correlated to more crime.