One of the president’s new executive orders will allow the Centers for Disease Control to conduct gun research again. The CDC is a horrible choice for this project, both because gun violence is has nothing to do with “disease control” and because the agency has a track record of poor research in this area.
Also, the holes in our knowledge are much smaller than some on the left would like to think — and many of the questions that have not been answered cannot be answered, simply because the tools of social science are not up to the task. Over at the Washington Post, Brad Plumer rounds up a list of topics on which the CDC’s input is supposedly sorely needed. In order:
How many guns actually exist in the United States?
There’s no official registry. The CDC will not create one, and it probably won’t improve on existing surveys, which indicate the number to be around 300 million, either. If the goal is to study the characteristics of gun owners, it’s hard to beat the General Social Survey.
How do guns get into the hands of people who commit crimes?
It would be nice to have a more recent survey on this question, but I went through some of the data yesterday.
What percentage of gun owners even commit gun crimes?
By “gun owners” do we mean people who buy guns legally? If so, one decent indicator is the proportion of concealed-handgun-permit holders who commit crimes — which is incredibly low. Another relevant fact is that murderers typically have prior criminal records.
If by “gun owners” we mean everyone who owns a gun, we have to divide the number of gun criminals by the number of gun owners. Even with research funding it would be hard to come up with precise definitions for those terms and solid numbers to match, and I’m not sure what we would gain from the result.
Is there a relationship between gun ownership levels and crime?
If we’re just looking for overall trends, it depends how you cut the data: Men are more likely to own guns and more likely to commit crimes; rural areas have high gun ownership and low crime; and so on. If the question is whether there’s a causal relationship, good luck: Social science is just not good at proving this type of thing. There is some evidence that gun ownership rises as crime rises in a given area, but it’s hard to tell which causes which.
Are criminals deterred by guns?
Some research indicates that allowing citizens to carry concealed weapons decreases crime. Other research shows concealed carry to make no difference at all, and a couple of studies even show that concealed carry increases crime. There is also some evidence from inmate surveys (for example, it seems there are few “hot” burglaries in the U.S. because thieves worry about being shot in the act). This debate has been going on for decades, and has involved many highly qualified researchers. The CDC will not resolve it.
Do limits on high-capacity magazines reduce the number of deaths?
If they make any difference at all, I doubt it’s big enough for any study to detect. In most situations magazine size doesn’t matter: Self-defense usually doesn’t require firing a shot, and it’s usually easy for a killer of innocent people to change magazines without being interrupted. Smaller magazines might make a gang shootout last a few seconds longer, but I doubt this would change the body count. When magazine size does matter, it might matter because the high-capacity magazine jammed when a smaller magazine would not have, or it might matter because changing magazines gave someone a chance to tackle a shooter.
Does firearm licensing and registration make people safer?
There are various ways it could make a difference in theory. One is that criminals could leave guns at crime scenes that are registered to themselves, and the registry could point the police to them; this does not seem to have happened in Canada. Also, registration could cause people to be more careful with their guns, but that is a difficult theory to test. A Johns Hopkins study from 2001 did find that states with registration saw a higher proportion of their crime guns come from out of state.
Do gun thefts increase crime?
Yes. (Is this a trick question?)
Does gun ownership affect whether people commit suicide?
It seems more likely than not. Further progress on this question won’t be possible until we find new ways of teasing variables apart (do guns make people more likely to kill themselves, or are people who want to own guns just more suicide-prone?).
What’s the best way to restrict firearm access to those with severe mental illnesses?
I’m not sure there are very many options. We need to keep a better list of people who are mentally ill in a way that makes gun ownership a bad idea, encourage mental-health professionals to contribute to that list, and use that list in background checks. We also need to increase the use of involuntary commitment and assisted outpatient treatment. It’s not a bad idea to keep statistics while we’re doing these things, of course, but we need to try things before we can analyze them.