Unfortunately, many contemporary discussions rely on misinterpretations of cross-sectional data. The New York Times recently conducted a cross-sectional study of murder rates in states with and without the death penalty, and found that “Indeed, 10 of the 12 states without capital punishment have homicide rates below the national average, Federal Bureau of Investigation data shows, while half the states with the death penalty have homicide rates above the national average” (Raymond Bonner and Ford Fessenden, “States With No Death Penalty Share Lower Homicide Rates,” New York Times, September 22, 2000, p. A1.). However, they erroneously concluded that the death penalty did not deter murder. The problem is that the states without the death penalty (Alaska, Hawaii, Iowa, Maine, Massachusetts, Michigan, Minnesota, North Dakota, Rhode Island, West Virginia, Wisconsin, and Vermont) have long enjoyed relatively low murder rates, something that might well have more to do with other factors than the death penalty. Instead one must compare, over time, how murder rates change in the two groups – those adopting the death penalty and those that did not.
Of course, I have other problems with the New York Times discussion. For example, the rates of gun ownership for Switzerland and Israel are ridiculously low. But my point above was that even if those numbers are taken as given, you still find the opposite relationship from what the New York Times was claiming.
The graph showing all non-US countries is shown here.
So what if we asked a different question? Including the US in the data shows the absurdity of the Small Arms Survey measure of gun ownership in 2007. They define it in such a way to exclude the military weapons in Swiss homes and to exclude most Israeli guns because the government technically owns them. Switching either or both of these countries so that they had a higher gun ownership rate than the US would offset their bias for the US rate. In any case, despite my objections to both cross-sectional data and the obviously bogus Small Arms Survey measure of gun ownership, here are the results with the US included. Doing this leaves the result for the world essentially unchanged and makes the relationship for OECD countries equal zero.