High gun ownership rates and high rates of mass shootings might seem like an obvious connection, but University of Alabama researcher Adam Lankford says his study is the first to show empirical evidence that the aforementioned ownership rate "is the strongest predictor of [a country's] number of public mass shooters." His quantitative analysis, based on 46 years of data on mass shootings around the world, found that the US has 5% of the world's population but 31% of its public mass shootings (defined as the deaths of at least four people and excluding things like domestic incidents and fatalities during robberies). The US has the highest civilian firearm ownership rate, and Lankford says in a press release it's no coincidence that the other four in the top five—Yemen, Switzerland, Finland, and Serbia—are also in the top 15 for mass shootings.
His study, which has not been published but was presented yesterday at the American Sociological Association's annual meeting, also found that more than 50% of shooters in the US use more than one weapon; in fact, American mass shooters are 3.6 times more likely to use multiple weapons. But while American mass shooters kill an average 6.87 victims, abroad that number stands at 8.81, possibly because US police are better trained in dealing with mass shootings. Lankford says that the main lesson from the study is an obvious one: Mass shootings can be reduced if the number of guns in circulation is reduced, as happened after a spate of shootings in Australia. "I didn't come into this study with any gun control agenda—I just let the data speak for itself," Lankford tells Deutsche Welle. "Whether people are willing to act on it is another question." (Read more mass shootings stories.)