This is the key question so many of us involved in the gun debate face. On a personal level, answering it has big implications for our families’ safety. As Amy discussed in a recent post, having a gun in the household increases the chances that someone in the household will die by gunshot, though even in households with guns there are many things you can do to keep your kids safer.

US and Japanese Flags With GunBut what about across the country? At the national level, the question has big implications for our country’s laws. Many people carry concealed or unconcealed weapons in public places out of fear of crime. Some people argue (see, for instance, here) that laws that allow easy access to guns and that allow guns to be carried in public places in the United States help to keep crime rates down. A recent study in The American Journal of Medicine – one of our country’s most prestigious sources of cutting-edge research in medicine and public health – concludes that that the answer is decidedly “No.”

The authors of this study examine rates of firearm ownership in 27 developed countries: from culturally relatively similar ones like Australia and New Zealand, to culturally quite different ones such as Japan. They also consider rates of major depressive disorder in those countries. Then they ask how firearm ownership and mental health problems in each country are related to the crime rate and the number of firearm deaths per person.

What they find is striking: the more guns in a country, the higher its rate of firearm deaths. The relationship is very strong, and holds up even when you don’t consider the countries at the extremes, such as the United States (high gun ownership, high firearm death rate) and Japan (low gun ownership, low firearm death rate). No matter how you slice the data, the more guns a country has, the more likely the average citizen is to die by gunshot. By contrast, there is a small, statistically significant relationship between mental illness and rates of gun deaths, but the association is very weak.

But some people might say that even if more guns means more gun deaths, criminals will be less likely to strike in countries where they fear that their potential victims could have a concealed weapon. In other words, maybe crime rates go down at the same time that would-be criminals are more likely to get killed. Unfortunately, once again the authors find that the answer is “No.” They find that there is no relationship between the number of guns per person in a country and the country’s crime rate. The U.S. happens to have a lot of guns and, in recent years, pretty low crime rates. But Japan has very few guns and even lower crime rates. And the UK and Israel have fewer guns than the U.S., but more crime.

Surely there must be some cases in which the presence of guns helps to prevent a crime, or in which potential victims kill would-be attackers. Still, this study has a very clear conclusion: on average and across the developed world, having more guns does NOT make countries safer.