Justin Briggs and Alex Tabbarok have a new paper providing evidence about guns and suicides. Here are some of the highlights from their blog post on that research, “It’s Simple: Fewer Guns, Fewer Suicides”:

Reverse Causality Not a Big Issue

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.

Much Less than Perfect Substitution into Other Modes of Suicide

…a percentage-point decrease in household gun ownership leads to between 0.5 and 0.9 percent fewer suicides….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.

Natural Experiment 1: Australian Gun Control Led to Fewer Gun Suicides

…following the 1996 killing of 35 people in Port Arthur, Australia, a strong movement for gun control developed in Australia. … these changes resulted in a reduction of the country’s firearm stock by 20 percent, or more than 650,000 firearms, and evidence suggests that it nearly halved the share of Australian households with one or more firearms. The effect of this reduction was an 80 percent fall in suicides by firearm, concentrated in regions with the biggest drop in firearms. Meanwhile there was little sign of any lasting rise in non-firearm suicides.

Natural Experiment 2: Prohibiting Soldiers from Taking Guns Home over the Weekend Led to Fewer Total Gun Suicides

In Israel most 18- to 21-year-olds are drafted into the Israeli Defense Forces and provided with military training—and weapons. Suicide among young IDF members is a serious problem. In an attempt to reduce suicides, the IDF tried a new policy in 2005, prohibiting most soldiers from bringing their weapons home over the weekends. Dr. Gad Lubin, the chief mental health officer for the IDF, and his co-authors estimate that this simple change reduced the total suicide rate among young IDF members by a stunning 40 percent. It’s worth noting that even though you might think that soldiers home for the weekend could easily delay suicide by a day or two, the authors did not find an increase in suicide rates during the weekdays.

If Lives Lost by Suicide are Valued at $8.4 Million Each, What is the Suicide Cost of a Gun?

Considering the value of life tells us that the true price of guns is higher than the monetary price by at least $2,635, the amount needed to be able to compensate for the expected loss of life.