You have heard the bogus claim that the US has 31% of all global mass shootings (with 5% of the world's population so 6x overrepresented), even though the US has a below average homicide rate compared to the rest of the world.
This number comes from a study by Adam Lankford and was widely cited even by Obama but never questioned even though it is absurd on its face considering the high amount of shootings and terror in the world. (There is a side issue that it hides non-gun related mass homicides like the car rammings in Europe or airplane terror attacks.)
Intentional homicide rate by country, as an example Mexico has 7x the murder rate of the US
How a Botched Study Fooled the World About the U.S. Share of Mass Public Shootings: U.S. Rate is Lower than Global Average
Lankford's original study: https://crimeresearch.org/wp-content/uploads/2018/08/Lankford-Violence-Victims-paper.pdf
Lankford's study was anti-scientific garbage, no data sources are given for the global number of shootings, he dodges debates and refuses to defend his methods which is a core requirement for any scientific study.
Lankford claims to have “complete” data on such shooters in 171 countries. However, because he has neither identified the cases nor their location nor even a complete description on how he put the cases together, it is impossible to replicate his findings. [= scientific garbage]
Lankford’s study reported that from 1966 to 2012, there were 90 public mass shooters in the United States and 202 in the rest of world. We find that Lankford’s data represent a gross undercount of foreign attacks. Our list contains 1,448 attacks and at least 3,081 shooters outside the United States over just the last 15 years of the period that Lankford examined. We find at least fifteen times more mass public shooters than Lankford in less than a third the number of years.
Even when we use coding choices that are most charitable to Lankford, his 31 percent estimate of the US’s share of world mass public shooters is cut by over 95 percent. By our count, the US makes up less than 1.43% of the mass public shooters, 2.11% of their murders, and 2.88% of their attacks.
Lott raised alarm bells that Lankford... did not do diligent research and refused to be transparent about his work, including not sharing his paper with others as he started his media blitz tour promoting the study in 2015... “Here’s an amazing thing, [Lankford] refuses to provide his list of cases, he refuses to explain exactly how he got it.
Lankford declined an interview request about his study and told Fox News in an email that he’s “not interested in giving any serious thought to John Lott or his claims.”