Efforts to pass new federal gun control laws in the aftermath of the Newtown massacre are making progress, while the NRA has argued that arming more citizens, even teachers in schools, is the answer to stopping gun deaths.

Two researchers, an evolutionary biologist and a mathematician at University of California, Irvine, have now stepped back from the emotional debate and taken a dispassionate look at which kind of gun policies would save more lives, both in a one-on-one attack (as in a homicide) and in a shooting in a crowd (as in a movie theater or mall). 

Their findings suggest that President Obama, who has said he supports the right for private individuals to own a gun, is not going far enough if he wants to prevent the greatest number of gun-related deaths.

The study starts by showing that the optimal survival strategies could be either of the extreme approaches: a total ban on private gun ownership, or a policy allowing anyone in the general population to get a gun.

Which of the two save the most lives in practice depends on a few key parameters that are at the center of the gun debate: how effectively illegal gun purchases are stopped; the fraction of people who purchase guns legally and also carry them around; and, finally, the extent to which a gun is effective at stopping an attacker. In mass shooting scenario, this also depends on the “efficiency” of the shooter’s weapon compared to any weapons in the crowd.

Using existing statistical data to put numbers to these factors, their model comes out squarely in favor of gun control. If a gun ban can be enforced in the U.S. at least as effectively as in the U.K., the results show such a policy would minimize the number of death compared to a gun buying free-for-all. The effect is strong enough that even a partial reduction in firearm availability is preferable to allowing more guns, the researchers write. 

The crucial factor is enforcement of gun laws. Private guns are banned in all but a few special circumstances in the U.K, which has one of the world’s lowest rates of gun deaths. Put simply, criminals are less likely to have guns. Only 8 percent of English and Welsh prisoners had owned an illegal gun in the year prior to their conviction, and of those, only 23 percent carried it with them at the time of their offense. Compare that to Mexico, a country that also has strict gun control but poor enforcement that leads to high rates of violence. If the U.S. had enforcement similar to Mexico, then yes, the authors acknowledge, we might be better off just arming everyone. 

The biggest exception to the study’s verdict in favor of a strictly-enforced gun ban is if a shooter were to open fire in a relatively large crowd of people, and then, only if this attacker is using, say, a handgun, rather than a very efficient automatic or semi-automatic weapon. In that one relatively rare situation, a policy encouraging gun ownership would have likely saved more lives than a policy making it harder for potential assailants to obtain a gun. (Personally, I wouldn’t want to live in such a society.)  

More than 1,600 people have died of gun violence in the U.S. since the Newtown tragedy, according to a tracking site on Slate. Because crime-related gun deaths are more common than mass shootings, the researchers had better data to work with in the one-on-one scenario, which is also where the policy focus needs to be. However, in either case, it’s clear more statistical studies are needed to inform the debate. 

Although the political tides have shifted since Newtown, no-one is seriously suggesting a total ban on gun ownership. Today, about 30 percent of Americans say they personally own a gun. In 2008, the U.S. Supreme Court found that the 2nd Amendment does guarantee an individual’s right to have a gun at home for self-defense. 

But, as this study illustrates, the war of words happening in Washington and in states and cities around the nation should be informed by more real evidence and data. And that is probably our best hope for ending the epidemic of gun violence. 

Ref: http://arxiv.org/abs/1301.7332: Calculating Effictive Gun Control Policies