Research on Guns and Road Rage
There is a new paper that is getting some attention that has just come out in the public health journal "Accident Analysis & Prevention." The paper by David Hemenway, Mary Vriniotix, and Matt Miller is entitled "Is an armed society a polite society? Guns and road rage." The paper is based on a survey of 2,400 drivers that the authors did. The survey asked respondents if they had made an obscene gesture to an opposing driver or whether they had aggressively followed another car. After that a series of descriptive questions were asked: gender, age, income, political views, urban/rural, and whether they have had a gun in their car at least one time over the last year. The authors make a simple comparison between those who have had a gun at least once in their car and those who didn't and say that the respective numbers are 23% and 16%. The authors imply that having a gun makes it more likely that one will engage in road rage.
There are multiple concerns with this analyis. Their questions make no attempt to ask whether a gun was in the car at the time the road rage incident occurred. Nor did they attempt to differentiate law-abiding permit holders from those who illegally possessed guns (e.g., asking respondents if they have a permit to carry a gun). This last point seems particularly important given that they want to make policy conclusions on concealed carry laws.
The paper also has some funny results. For example, Liberals are apparently much more likely to engage in road rage than conservatives and the difference is larger than the difference between those who did and did not have a gun at least one time in their car over the last year. This variable is apparently never investigated, but presumably they are also concerned about liberals being allowed to drive cars.
Finally, surveys can be a useful first approximation, but there is in fact much more direct evidence available on the behavior of concealed handgun permit holders. Despite almost four million Americans currently having permits to carry concealed handguns and some states having these laws for as long as eighty years, there is only one case in Alabama where a permitted concealed handgun was used to commit road rage. There are also other much more direct mesaures that indicate that people who have concealed handgun permits and who thus carry guns in their cars legally. For example, the fact that permit holders tend to be extremely law-abiding and lose their permit for violating gun regulations occurs for only hundredths or thousandths of one percent of permit holders. If they used their guns in the way that the authors of this study fear, their permits would have been revoked.
I have asked the authors for their data, but we will see when and how quickly I get it.
UPDATE: Hemenway is unwilling to provide the data for me to look at. My response is that if he or his co-authors are making comments to the press as they have, he is under an obligation to give out the data used in this paper. Despite putting together the largest data sets that have been put together on crime, I give out those data sets when the papers get media coverage even when they haven't been published yet. Hemenway's paper has been published. (The accuracy of this update was confirmed with my intern who talked to Hemenway and emailed him about obtaining this data. I had previously emailed one of the authors about obtaining the data, but I didn't receive a response.)
UPDATE 2: After a second telephone call, Hemenway said that while he will not give out the data used in the paper, he may reconsider providing a portion of the data, but that he can't make a decision before talking to his co-authors. He is also very busy and would not say when he would check into even this. (The accuracy of this update was confirmed with my intern who talked to Hemenway about obtaining this data.)
UPDATE 3: Well, it is official. Hemenway is not going to make his data available. This is true even though I have only asked for the data used in the published paper, and I am also happy to promise to use the data to only evaluate the research that the authors have already published. Hemenway complains about the comments that I have made regarding his study and concludes that: "no one on our research team believes that it will advance the science to provide even portions of the dataset semi-exclusively to Dr. Lott at this time." Of course, Hemenway inaccurately implies that I ever wanted the data set "semi-exclusively." I think that they should provide the data to everyone. I am probably just the only person to ask for it. (This update is based an email that Hemenway sent to Chris DeMuth, the president of AEI.)
Frank Main, the crime reporter for the Chicago Sun-Times, is the only reporter who has written on this study who mentions criticisms of the Hemenway, Vriniotix, and Miller research.
Clayton Cramer, Say Uncle, Geek with a .45, and The Donovan also have some notes on this research.
Correction: The original note mentioned that only one regression had been run by these authors. In fact, it turns out that four regressions had been run. The points listed above are now correct.