Long suggested anecdotally, researchers have now confirmed that mass shootings in the US can spur an increase in handgun sales. Shootings that result in a large number of fatalities, however, have the opposite effect.
In a paper published in the journal JAMA Network Open, Gina Liu from the University of Oxford, UK, and Douglas Wiebe from the University of Pennsylvania, US, compare numbers and timing of background checks for gun purchases with all shootings resulting in five or more fatalities between 1 November 1998 and 30 April 2016.
During the period there were 124 mass killings, and 233,996,385 entries logged on the US National Instant Criminal Background Check System.
The researchers found that following 26 of the shootings – 21% of the total – gun purchases surged in the immediate aftermath. However, following 22 – 17.7% – sales actually dropped.
The key driver for shootings that triggered increased purchases, Liu and Wiebe report, was media coverage – more stories written or broadcast about a particular incident tended to correlate with an uptick in background checks.
However, shootings that resulted in many deaths were followed by a drop in checks. This, the researchers say, “was an unexpected finding of the study”.
It may not, however, be an indication of revulsion on the part of the gun-buying public, much less an indication of a resolve, however temporary, to move away from the cycle of gun ownership and violent gun use.
“One potential hypothesis is regression to the mean,” the researchers write, “especially given that some shooting events associated with decreases in gun purchasing occurred closely after extremely high-profile shootings associated with large increases in all forms of gun purchases.”
Liu and Wiebe note that although they often attract significant media attention – and generate widespread fear in the community – mass shootings in the US remain “relatively rare” compared to other forms of gun violence.
Firearm death and injury, they note, comprise “a serious public health crisis”. Deaths from guns outnumber deaths from vehicle accidents by a hefty margin. However, out of 30,000 yearly gun deaths, mass shootings account for only about 1% of the total.
The observed decrease in background checks after high-fatality shootings is perhaps grounds for optimism, but Liu and Wiebe, drilling down into the data, are ambivalent in their findings.
Seven mass shootings, they note, resulted in increased background checks in all seven categories of available guns. Only two resulted in across-the-board decreases.
“The mechanisms underlying decreases of gun purchases may operate on a smaller scale than the mechanisms underlying increases of gun purchases,” they suggest.
They also note that the background check data fails to capture an estimated 50% of total gun purchases, because these occur outside gun shops or pawn shops and thus fall outside reporting requirements in several states.
Andrew Masterson is a former editor of Cosmos.