Few topics of discussion can evoke a more passionate (or politically charged) emotional reaction than the subject of mass shootings. While there is no question that mass shootings are horrific, opinions differ widely—particularly in the United States—on what causes mass shootings and what needs to be done about them. Mass shootings are part of the larger issue of overall gun violence, which is notably higher in the United States than in other wealthy and developed countries. Countries with similar levels of gun-related deaths tend to be still-developing countries mired in violent civil unrest, revolution, or war.
The U.S. endures the most mass shootings in the world, with—depending upon one's definition of a mass shooting (see next section)—somewhere between 21 and more than 600 in 2020. A 2015 Politifact article correcting then-President Barack Obama’s statement that no other advanced country experiences mass shootings like the U.S. cited data from 2000 to 2014 to prove that mass shootings do indeed happen in other advanced countries. However, the article conceded that the U.S. experienced 133 shootings during that period, while the next-highest total was Germany with six.
That said, mass shootings actually comprise only a fraction of the overall gun deaths in the United States. In fact, roughly two-thirds of all gun-related deaths in the U.S. are suicides. In 2016, for example, 37,353 gun deaths occurred in the United States. Of these, 22,938 were suicides, and 14,415 were homicides. Within the homicides, 71 were classified as the result of a mass shooting.
One of the main causes for the vast range of stances on mass shootings is that reliable data on mass shootings can be notoriously difficult to obtain—what's more, the data that does exist is often incompatible with data from other sources. No official, universally accepted definition for a mass shooting exists. Rather, each stat-tracking organization has its own qualifying criteria. For example, the United States Federal Bureau of Investigations (FBI) defines a mass shooting as a single attack that happens in a public place and in which three or more people are killed with a firearm. However, most other stat trackers require at least four fatalities. As a result of these mismatched definitions, database-to-database differences are both common and confounding.
Similarly, some databases include events in which at least four people were wounded, but not necessarily killed. Others do not. Some databases include occurrences in which the shooter killed only family members (but still in a public place, such as a restaurant). Others do not. Some databases include organized terrorist attacks, armed robberies gone wrong, and gang-related shootings. Other databases discard some or all of these incidents. In fact, in a 2019 study that compared four different databases, the number of mass shooting events recorded in the U.S. for the year 2017 ranged from a low of 11 to a high of 346. Clearly, a significant error margin exists, particularly when creating country-to-country comparisons.
Although events in the U.S. tend to get the lion's share of media exposure, mass shootings are clearly a worldwide issue. The following is an alphabetized list of just some of the [developed countries] other than the United States that have experienced one or more mass shootings in the past few decades: Azerbaijan, Belgium, Bosnia and Herzegovina, Brazil, Finland, France, Germany, India, Israel, Italy, Nigeria, Norway, the Philippines, Russia, Serbia, Spain, and Switzerland.
Exactly how mass shootings in the U.S. compare to those in other countries is a highly disputed subject. In a widely publicized study originally released in 2015, the pro-gun nonprofit Crime Prevention Research Center (CPRC) compared the annual number of mass shooting deaths per million people in the U.S. to that of Canada and several European countries from 2009 to 2015. The result? Norway led the world with 1.88 deaths per million, followed by Serbia, France, and Macedonia. Where did the U.S. rank? 11th place.
In addition, a 2018 CRPC study ranked the U.S. at number sixty-four in the world in terms of mass shooting rates per capita.
Many statisticians believe the reason the CRPC study's results seem so counterintuitive is that they are incorrect. One of the more detailed analyses appeared on the fact-checking website snopes.com and concluded that the CRPC report used “inappropriate statistical methods” which led to misleading results.
According to the fact-checkers' analysis, one of those inappropriate methods was the leaving out of the many European countries that had not experienced a single mass shooting between 2009-2015. This data would not have changed the position of the U.S. on the list, but its absence could lead a reader to believe—incorrectly—that the U.S. experienced fewer mass shooting fatalities per capita than all but a handful of countries in Europe.
A more important oversight was the report's use of average deaths per capita instead of a more stable metric. Because of the smaller populations of most European countries, individual events in those countries had statistically oversized influence and warped the results. For example, Norway’s world-leading annual rate was due to a single devastating 2011 event, in which far-right extremist Anders Behring Breivik gunned down 69 people at a summer camp on the island of Utøya. Norway had zero mass shootings in 2009, 2010, 2012, 2013, 2014, and 2015.
An easy, though arguably insensitive, way to illustrate the shortcomings of this approach is to apply it to the 9/11 attacks, which killed 2,977 people in the United States on a single day in 2001. Running that data through the CRPC formula yields the following statistic: Plane hijackings by terrorists caused an average of 297.7 deaths per year in the U.S. from 2001-2010. This is mathematically accurate, but it gives a badly distorted impression of what actually happened during those ten years.
In addition, the CRPC study went a step further and computed average annual deaths per capita. Critics argue this further warps the data, because Norway’s population is a fraction of the U.S. population. As a result, Norway’s death rate came out more than 20 times higher than that of the U.S.—which tallied 66 deaths in 2012 alone (nearly matching Norway's total for the full study) and averaged at least one mass shooting death per month for the entire seven-year data set.
The fact-checking analysis goes on to suggest that instead of computing each country's average, or mean mass shooting deaths, a better method would be to compute the median, or typical, number of deaths. The median is considered by many statisticians to be better insulated against individual outlier events (such as the Norway massacre) that can skew results. This leads to a more accurate day-to-day impression and country-to-country comparison. Using the CPRC’s own data and more precise per-year population data from World Bank (the original study used only 2015 population data) to solve for the median, the more statistically sound analysis results in a notably different list:
Using the median analysis, the United States is the only country examined that shows a propensity for mass shootings. The data itself supports this interpretation, as the United States endured mass shooting events all seven years, but the other countries all experienced mass shootings during only one or two years. Thus, in a typical year, most countries experience zero mass shooting deaths, while the US experiences at least a few.
Many other studies and articles also offer opinions or interpretations counter to that of the CPRC. For example, a 2019 paper from Econ Journal Watch, a scholarly economics journal, notes that the CPRC data included many events that would be considered military or terrorist actions, such as when 200 insurgents in Ethiopia attacked an oil field and shot 74 people. While these are undeniably tragic deaths, the EJW proposes that they are not what most people associate with the term "mass shooting" and should not be included.
Additionally, a 2021 BBC article used data from the FBI and the Las Vegas Police to point out that eleven of the thirteen deadliest mass shootings in the past 30 years in the United States occurred between 2001 and 2021 (implying that mass shootings are becoming more frequent and more deadly). A 2016 paper from the University of Alabama compared 171 countries from 1966 to 2012 and concluded that the United States accounted for only 5% of the world’s population, but 31% of its mass shootings. CPRC has questioned the legitimacy of this report's data.
Deaths per 1M
The United States has the most mass shootings with 133 between 2000 and 2014. Depending on the definition, numbers for 2020 ranged from 21 to 600 American incidents.