People who own guns are more likely than non-gun owners to die by suicide, according to a study published last month led by Harvard School of Public Health professor Matthew Miller.

The study, entitled “Firearms and Suicide in the United States: Is Risk Independent of Underlying Suicidal Behavior?”, examined data on suicide rates and gun owenership from across the United States.

Miller said that the purpose of the study was to attribute increases in overall rates of suicide to differing gun laws by controlling for other variables.

“What we did in this study was address...potential confounding variables,” Miller said. “Maybe people are just more suicidal in high gun-ownership states, but we found that this is not the case.”

The vast majority of people who attempt suicide and fail, Miller said, do not go on to die from suicide. Miller argued that suicide rates could be lowered by simply taking away the option of guns, because guns are so much more lethal than other methods of suicide.

According to Miller, the recently published study is not intended to make any policy recommendation regarding the issue of gun control.

“This is a paper that underscores prior work showing that a firearm in a house puts the entire family at a greater risk of suicide,” Miller said. “People should keep that in mind when making the decision to buy a firearm.”

Miller’s study adds to an already large and controversial literature on gun ownership rates and violence, which includes studies documenting both positive and negative associations of gun ownership and violence. For instance, a 2007 paper published in the Harvard Journal of Law and Public Policy entitled “Would Banning Firearms Reduce Murder and Suicide?” found a negative correlation between legal access to firearms and homicides across countries.

According to the study’s co-author Gary Mauser, criminology professor at Simon Fraser University, the study isolated the causal effect of gun ownership on violence by comparing countries with similar cultures and geographies.

“For example, Luxembourg has virtually no gun owners, but has significantly higher murder rates than neighboring countries without gun bans,” Mauser said.

David Hemenway ’66, director of the Harvard Injury Control Research Center, criticized the research methods used in Mauser’s study, expressing skepticism about the broader significance of the findings.

“They didn’t do a ‘study’—they just put out some data,” Hemenway said, claiming that Mauser’s paper suffered from methodological errors.

Hemenway added that other international comparisons have found that gun ownership is positively correlated with homicide rates.

Mauser, however, wrote in an email that Hemenway’s claim about the correlation between gun ownership and homicide only reflects the medical literature.

“He ignores the many studies by criminologists and economists that find [that stricter gun control laws are correlated with higher rates of homicide], and employ much better methodological designs,” Mauser wrote.