Debunking the Defensive Gun Use Myth


The Myth of Defensive Gun Use

**Note – This article appeared in Politico on 1/14/2015

In the early hours of Nov. 2, 2013, in Dearborn Heights, Michigan, a pounding at the door startled Theodore Wafer from his slumber. Unable to find his cell phone to call the police, he grabbed the shotgun he kept loaded in his closet. Wafer opened the door and, spotting a dark figure behind the screen, fired a single blast at the supposed intruder. The shot killed a 19-year-old girl who was knocking to ask for help after a car accident.

Shortly after midnight on June 5, 2014, two friends left a party briefly. Upon returning they accidently knocked on the wrong door. Believing burglars were breaking in, the frightened homeowner called the police, grabbed his gun and fired a single round, hitting one of the confused party-goers in the chest.

On Sept. 21, 2014, Eusebio Christian was awakened by a noise. Assuming a break-in, he rushed to the kitchen with his gun and began firing. All his shots missed but one, which struck his wife in the face.

What do these and so many other cases have in common? They are the byproduct of a tragic myth: that millions of gun owners successfully use their firearms to defend themselves and their families from criminals. Despite having nearly no academic support in public health literature, this myth is the single largest motivation behind gun ownership. It traces its origin to a two-decade-old series of surveys that, despite being thoroughly repudiated at the time, persists in influencing personal safety decisions and public policy throughout the United States.

In 1992, Gary Kleck and Marc Getz, criminologists at Florida State University, conducted a random digit-dial survey to establish the annual number of defensive gun uses in the United States. They surveyed 5,000 individuals, asking them if they had used a firearm in self-defense in the past year and, if so, for what reason and to what effect. Sixty-six incidences of defensive gun use were reported from the sample. The researchers then extrapolated their findings to the entire U.S. population, resulting in an estimate of between 1 million and 2.5 million defensive gun uses per year.

The claim has since become gospel for gun advocates and is frequently touted by the National Rifle Association, pro-gun scholars such as John Lott and conservative politicians. The argument typically goes something like this: Guns are used defensively “over 2 million times every year—five times more frequently than the 430,000 times guns were used to commit crimes.” Or, as Gun Owners of America states, “firearms are used more than 80 times more often to protect the lives of honest citizens than to take lives.” Former Republican Sen. Rick Santorum has frequently opined on the benefits of defensive gun use, explaining: “In fact, there are millions of lives that are saved in America every year, or millions of instances like that where gun owners have prevented crimes and stopped things from happening because of having guns at the scene.”

It may sound reassuring, but is utterly false. In fact, gun owners are far more likely to end up like Theodore Wafer or Eusebio Christian, accidentally shooting an innocent person or seeing their weapons harm a family member, than be heroes warding off criminals.

How To Manufacture A Statistic

In 1997, David Hemenway, a professor of Health Policy at the Harvard School of Public Health, offered the first of many decisive rebukes of Kleck and Getz’s methodology, citing several overarching biases in their study.

First, there is the social desirability bias. Respondents will falsely claim that their gun has been used for its intended purpose—to ward off a criminal—in order to validate their initial purchase. A respondent may also exaggerate facts to appear heroic to the interviewer.

Second, there’s the problem of gun owners responding strategically. Given that there are around 3 million members of the National Rifle Association (NRA) in the United States, ostensibly all aware of the debate surrounding defensive gun use, Hemenway suggested that some gun advocates will lie to help bias estimates upwards by either blatantly fabricating incidents or embellishing situations that should not actually qualify as defensive gun use.

Third is the risk of false positives from “telescoping,” where respondents may recall an actual self-defense use that is outside the question’s time frame. We know that telescoping problems produce substantial biases in defensive gun use estimates because the National Crime Victimization Survey (NCVS), the gold standard of criminal victimization surveys, explicitly catalogs and corrects for it.

Specifically, NCVS asks questions on the household level every 6 months. The first household interview has no time frame. Follow-up interviews are restricted to a six-month time frame and then NCVS corrects for duplicates. Using this strategy, NCVS finds that telescoping alone likely produces at least a 30 percent increase in false positives.

These sorts of biases, which are inherent in reporting self-defense incidents, can lead to nonsensical results. In several crime categories, for example, gun owners would have to protect themselves more than 100 percent of the time for Kleck and Getz’s estimates to make sense. For example, guns were allegedly used in self-defense in 845,000 burglaries, according to Kleck and Getz. However, from reliable victimization surveys, we know that there were fewer than 1.3 million burglaries where someone was in the home at the time of the crime, and only 33 percent of these had occupants who weren’t sleeping. From surveys on firearm ownership, we also know that 42 percent of U.S. households owned firearms at the time of the survey. Even if burglars only rob houses of gun owners, and those gun owners use their weapons in self-defense every single time they are awake, the 845,000 statistic cited in Kleck and Gertz’s paper is simply mathematically impossible.

Despite survey data on defensive gun uses being notoriously unreliable, until recently there have been only scattered attempts at providing an empirical alternative. The first scientific attempt was a study in Arizona, which examined newspaper, police reports and court records for defensive gun uses in the Phoenix area over a 100 day period. At the time Arizona had the 6th highest gun death rate, an above average number of households with firearms and a permissive “shall issue” concealed carry law meaning that defensive gun use should be higher than the national average.

Extrapolating Kleck-Gertz survey results to the Phoenix area would predict 98 defensive killings or injuries and 236 defensive firings during the study period. Instead, the study found a total of 3 defensive gun uses where the gun was fired, including one instance in which a feud between two families exploded into a brawl and several of the participants began firing. These results were much more in line with (but still substantially less than) extrapolated NCVS data, which predicted 8 defensive killings or injuries and 19 firings over the same time frame.

Brand new data compiled by the Gun Violence Archive, a non-partisan organization devoted to collecting gun violence data, further confirms Hemenway’s suspicion that Kleck and Getz’s findings are absurd. The archive found that for all of 2014 there were fewer than 1,600 verified defensive guns uses, meaning a police report was filed. This total includes all outcomes and types of defensive uses with a police report—a far cry from the millions that Kleck and Getz estimated.

Many gun advocates will protest at this point that not all defensive gun uses are reported to the police, which is true. However, Kleck’s surveys and the NCVS reports indicate that more than 50 percent of such incidents are reported to the police. This would indicate 3,200 defensive uses on an annual basis, still well short of what surveys suggest. Further, if there actually are 50,000 defensive gun uses as NCVS’ data suggests, or more than 1 million as Kleck and Getz’s surveys claim, that would mean only 3.2 percent or 0.16 percent respectively of defensive gun uses are reported to the police. Believing that such a small fraction of incidents are reported is indulging in fantasy.

Kleck and Gertz often defend their paper by claiming that their results are consistent with the findings of other private surveys. They explain that the reliability of a survey should be judged by the degree to which it coheres with the estimates of other surveys. However, using a tool we know to be flawed, over and over again, does not increase the quality of estimates deriving from the tool—it merely produces convergence to an arbitrary number. Surveys, for example, regularly show that men have sex with women more often than women have sex with men. Survey results don’t mean anything if they don’t pass muster with reality.

Criminal Uses Outnumber Self-Defense Uses

The spurious conclusions in these surveys don’t just distort the pro-gun community’s perception of defensive gun use. For example, the claim that millions every year shoot their guns in self-defense has led some to posit that there are more defensive gun uses than criminal uses. This assertion is inexplicable—not backed by any substantive evidence. We have yet to find a single study examining the question that does not show that criminal uses far outweigh defensive uses.

You might hear gun advocates substantiate this claim by comparing inflated survey numbers like Kleck’s with NCVS crime numbers. But defensive gun use surveys and the NCVS use different methodologies. To compare those two data sets is to break one of the most important laws of statistical analysis: You must always compare likes to likes.

And indeed, comparing NCVS results to NCVS results yields a very different picture—that more than 9 times as many people are victimized by guns than protected by them. Respondents in two Harvard surveys had more than 3 times as many offensive gun uses against them as defensive gun uses. Another study focusing on adolescences found 13 times as many offensive gun uses. Yet another study focusing on gun use in the home found that a gun was more than 6 times more likely to be used to intimidate a family member than in a defensive capacity. The evidence is nearly unanimous.

Most Self-Defense Uses Are Illegal

Beyond the defensive gun use versus criminal use dichotomy lies an important question: Are all defensive gun uses good? Undergirding gun advocates’ rhetoric touting the millions of defensive gun uses every year is the assumption that these uses are necessarily good. However, most cases of defensive gun use are not of gun owners heroically defending their families from criminals.

Kleck himself admitted in 1997, in response to criticism of his survey, that 36 to 64 percent of the defensive gun uses reported in the survey were likely illegal—meaning the firearm was used to intimidate or harm another person rather than for legitimate self-defense. His conjecture was confirmed by a Harvard study showing that 51 percent of defensive gun uses in a large survey were illegal according to a panel of 5 judges. This was even after the judges were told to take the respondents at their word, deliberately ignoring the tendency of respondents to portray themselves in a positive light.

Let’s assume for a moment that Kleck and Getz’s estimates are accurate. Rather than being a boon to civilized society, then, these estimates of 1 million to 2.5 million defensive gun uses annually would instead indicate an epidemic of irresponsible gun owners—millions! Lucky for us, despite what the NRA’s favorite criminologists claim, this clearly isn’t the case.

The myth of widespread defensive gun use is at the heart of the push to weaken already near catatonic laws controlling the use of guns and expand where good guys can carry guns to bars, houses of worship and college campuses—all in the mistaken belief that more “good guys with guns” will help stop the “bad guys.” As Wayne LaPierre of the NRA railed in the wake of the Sandy Hook shooting: “The only thing that stops a bad guy with a gun, is a good guy with a gun.”

But the evidence clearly shows that our lax gun laws and increased gun ownership, spurred on by this myth, do not help “good guys with guns” defend themselves, their families or our society. Instead, they are aiding and abetting criminals by providing them with more guns, with 200,000 already stolen on an annual basis. And more guns means more homicides. More suicides. More dead men, women and children. Not fewer.

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