When the United States manufactures and imports more firearms, firearm homicide rates in Central American and Caribbean countries also increase, a study led by University of Michigan researchers found.

The link between increased availability of firearms and deadly violence in other parts of the world highlights the potential international repercussions of greater firearm availability from the U.S., say the researchers, who zeroed in on the impact of firearm production and imports.

“By analyzing trends not just in U.S. firearm manufacturing but also in U.S. firearm imports, we were able to see that firearm availability in the U.S. was significantly associated with firearm-related homicides in Central America and the Caribbean,” said Eugenio Weigend Vargas, postdoctoral research fellow at U-M’s Institute for Firearm Injury Prevention.

“These findings suggest that the illegal flow of U.S. firearms is an issue that could be affecting entire regions.”

To better understand the effect of U.S. firearms manufacturing and imports on homicides in other countries, researchers examined data from the Global Burden of Disease, a study that estimates annual mortality figures and rates of more than 360 diseases and injuries per 100,000 people across more than 200 countries. Information from the Bureau of Alcohol, Tobacco, Firearms and Explosives 2021 Report on Firearms Commerce in the United States was also used.

The analysis showed that between 1991 and 2019, as annual firearms manufacturing in the U.S. increased by one million units, the Central American/Caribbean region saw an increase of 1.42 homicides per 100,000 people—roughly 3,020 firearm-related homicides per every 1 million firearms in the U.S. market.

Researchers also found that there was no association between increased firearm production and nonfirearm homicides, an indication that the relationship is specific to homicides involving firearms.

Co-authors include: Zainab Hans, Douglas Wiebe and Jason Goldstick, all of U-M.