Sunday, August 23, 2009

Self Defense Gun Use vs. Crminal Gun Use

In my opinion, this question is at the very heart of the gun control debate. If what many pro-gun people say is true, that DGUs far outnumber criminal use, gun-control proponents would be hard pressed to continue with their argument. I never accepted the pro-gun claims.

The Harvard Injury Control Research Center recently published a report about this very thing. First they described how the survey questions might be presented.

Approach 1: ask everyone about gun use;

Approach 2: ask only those who first report that someone tried to commit a crime against them--and assume that a negative response to this screener question means that the respondent could not have experienced either a genuine self-defense or criminal gun use. For example, a preemptive strike would not be considered a self-defense gun use.

Approach 2, which obtains gun information from only a subset of those asked in Approach 1, yields much lower estimates of both types of gun uses (see McDowall et al. 2000 for the differences with respect to self-defense gun use).

The results were as follows:

Approach 1: 10 million (Box A criminal) 2.5 million (Box B defensive)

Approach 2: 800,000 (Box C criminal) 80,000 (Box D defensive)

One of the most fascinating things for me is that approach 1, maintains the famous 2.5 million DGUs but puts the criminal figure at four times that, 10 million.

No one likes Approach 2, which is the one used by the NCVS.

The Harvard researchers go on to point out another important factor, one which I find of particular interest. Some, they say most, of the 2.5 million supposed defensive uses of guns are nothing of the sort.

Regular citizens with guns, who are sometimes tired, angry, drunk, or afraid, and who are not trained in dispute resolution, have lots of opportunities for inappropriate gun uses. People engage in innumerable annoying and somewhat hostile interactions with each other in the course of a lifetime. It should not be surprising that inappropriate, socially undesirable "self-defense" gun uses by people who believe they are law-abiding citizens outnumber the appropriate and socially beneficial use of guns.

Although most of the reported self-defense gun uses from Approach 1 surveys seem more like criminal uses, even if one believed they were all genuine socially beneficial uses, the number of criminal gun uses would still vastly exceed the number of self-defense gun uses in the United States. No survey using similar methodology to determine both criminal and self-defense use has ever found otherwise.

What's your opinion?


  1. Something to consider MikeB...

    What would be your feeling about the validity of a report in which the author of that report cites himself in the footnots?

    A total of 9 footnotes and 3 of them are of the report's author.

    Not to mention the fact that the whole thing was funded by the Joyve Foundation.

    Nice try, though. "A" for effort.

  2. My first response: How silly do you feel now about constantly throwing out the 200:1 ratio of defensive gun use to criminal use? There's not a single statistic to support that, so you need to stop. The worst ratio here is 10:1 (which is still a huge discrepancy).

    My second response is: So what? You've proven that by any standard 10's of thousands to millions of people use weapons for self defense every year. Now if we passed a gun ban (these studies are all about supporting gun control) whom would that ban most disarm? The criminals or the tens of thousands of law abiding? It would disarm some percentage of the former (a small percentage I would say) but nearly 100% of the latter.

    So really, you've once again just found research that proves the value of civlian gun ownership!

    Thank you!

  3. This is one of those groups that already have an agenda to start with and will always make their "data" conclude their pre-determined goal. The Joyce Foundation would not agree to fund them otherwise.

  4. Given that the FBI reports that there are a total, in all of the United States, of 1.4 million violent crime, it seems rather fantastic to suggest that the actual number of violent crimes, just involving firearms, is more than 7 times that amount.

    They seem to be basing this off just two unrelated surveys, which is a bit suspect.

    Either way, it's a tough number of measure. I don't know if I've ever really believe 2.5 million, which would indicate there's an awful lot of unreported crime out there. What's the threshold of defensive gun use? If I hear a noise in the night, and go to investigate, pistol in hand, is that a DGU? Maybe it is if I actually find someone in the house and they take off running. But it seems to have to put some kind of base criteria in order to categorize the use as really defensive or not. By the barest category, I've had several DGUs. But I've never used a firearm to prevent myself from being a victim of a violent crime, or defended myself against someone in my home.

    You'd also have to figure the DGU number would have to hover below the total number of violent crimes, combined with the total number of residential hot burglaries, which number about 440,000. So absent a great number of unreported violent crime or residential hot burglaries, which seems unlikely to me, 2.5 million seems pretty high. I think 80,000 might be a bit low, since you have to figure that of the 440,000 households that were hot burgled, that about 40% of those would likely have a firearm. If only half those people were aware there was someone in their home, that would put the number of DGUs at 88,000 right there. That kind of DGU, where someone uses a firearm to defend their person against a burglar in the house, is probably the most common, since not a lot of people carry guns. I'd believe 100,000 DGUs. But I doubt the number is all that much higher, though I'd believe it could be double that, depending on how much unreported crime there is.

  5. Sebastian, "Inappropriate gun use" is what those 10 million were supposed to be. I thought it was high too, but it's not what you said, obviously since the total number of crimes on the books is so much lower than that.

    Thanks for that interesting calculation of the hot-burgled homes and from that estimating the number of DGUs.