Do gun restrictions help reduce gun deaths?

The researchers reviewed the findings from 130 studies conducted from 1950 to 2014 in 10 countries that had overhauled their gun law, mostly in the developed world, including the U.S., Australia, and Austria. A few studies looked at gun laws in middle-income countries, including Brazil, Colombia and South Africa.

"In most countries, we saw evidence of reduction in the firearm death rates after the enactment of firearm legislation" said Julian Santaella-Tenorio, a doctoral student in Epidemiology at Columbia University's Mailman School and the study's lead author.

Santaella-Tenorio and his Columbia co-authors, Professors Magdalena Cerdá and Sandro Galea, also found evidence that specific laws, such as background checks and rules on storage, reduced specific kinds of gun deaths including intimate partner homicides and firearm unintentional deaths in children, respectively.

By comparison, laws in place about carrying concealed weapons or standing your ground either had no effect on gun deaths or increased gun violence. "While our review is not proof that gun laws reduce violence, and also taking into account that for some countries there are very few papers examining firearm laws effects, we did see evidence showing an association between firearm laws and a decline in firearm homicide and suicide rates," noted Santaella-Tenorio.

"Since we limited our review to changes in firearm policy and not ownership in general or other types of policy, the debate should not end here."