In the year since Adam Lanza used a Bushmaster rifle to gun down 20 children in Newtown, Conn., the discourse on gun control has focused on mass shootings and homicides. That's not surprising.
But if we want to talk about the effects of guns, we should remember this: In a typical year, suicides outnumber homicides by 3 to 1, and a majority of suicides are by firearm. Suicides come in ones and twos, here and there; they rarely make the national news.
But the national conversation about guns, and about gun control, should include the relationship between guns and suicide. We recently analyzed a decade's worth of data on guns and suicides in the United States and we found that the relationship is clear: more guns, more suicides.
Suicide is neglected compared with the large quantity of research on the relationship between homicides and guns, a relationship that remains controversial because it's difficult to demonstrate causality. Places with lots of guns may have high homicide rates, but is this because guns cause homicide or because homicides cause people to buy guns?
Or could a third factor — say, a general lack of social trust or high violence in a region — be causing both homicides and gun possession? The relationship between suicides and guns is much easier to tackle because it's unlikely that an increase in the number of suicides in a community would cause an increase in local gun ownership.
So in a new paper published in the International Review of Law and Economics, we studied the relationship between guns and suicide in the United States from 2000 to 2009. Using five measures of gun ownership and controlling for other factors associated with suicide, such as mental illness, we consistently found that each 1 percentage-point increase in household gun ownership rates leads to between 0.5 and 0.9 percent more suicides. Or, to put it the other way, a percentage-point decrease in household gun ownership leads to between 0.5 and 0.9 percent fewer suicides.
Are the people not killing themselves with guns simply committing suicide by other means? Some are — but not all. While reduced household gun ownership did lead to more suicides by other means, suicides went down overall. That's because contrary to the "folk wisdom" that people who want to commit suicide will always find a way to get the job done, suicides are not inevitable. Suicides are often impulsive decisions, and guns require less forethought than other means of suicide — and they're also deadlier.
Our research had to overcome the fact that no one knows with great precision how many guns there are in America, how many households own a gun, how gun ownership varies demographically and geographically, what types of guns there are, or how guns are used. In part that's because in 1996, Congress banned the CDC from funding any research to "advocate or promote gun control."
But gun advocates and supporters of Second Amendment rights shouldn't assume that more research simply means more arguments against guns. We are eager, for example, to see more studies on the defensive use of guns, a phenomenon about which there is currently very little trustworthy data. Moreover, better research might find ways of reducing gun violence without violating Second Amendment rights. Indeed, reducing gun violence could be one of the best ways of reducing the demand for gun control.
Suicide is a leading cause of death among adolescents and young adults, and limiting access to guns during those formative, sometimes unsteady years can have a real effect on suicides.
If more guns lead to more suicides, should we ban guns? Not necessarily. We find that a 1 percentage-point increase in the household gun-ownership rate increases suicides by at most 0.9 percent. There are 114 million households in the United States, so a 1 percentage-point increase in ownership means approximately 1.1 million more households with guns. Since there are relatively few suicides, this translates into 345 more suicides, at most. In this sense, guns are relatively benign. Most guns are never involved in a suicide or a homicide.
Guns in the home are a risk factor for suicide, and the risk is especially great if there is a depressed adolescent living at home. Unfortunately, people don't always weigh risks carefully. In one study, even when strongly recommended by mental health professionals to do so, most parents of a depressed adolescent didn't remove their guns from their home. It's also disturbing that guns were least likely to be removed when the father of the depressed adolescent had a drinking or drug problem of his own.
Suicide gets less attention, less funding and less concern than many other kinds of deaths, but suicide and its relationship to mental health, social isolation and firearm access deserve our full attention and concern.
Justin Briggs is a graduate student at George Mason University. Alex Tabarrok is Bartley J. Madden Chair and professor of economics at George Mason University.
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