Do gun laws reduce gun deaths? New study says 'yes,' but data are thin.

Do more gun laws lead to fewer gun deaths?

The simple answer is “yes,” according to study released Wednesday in the Journal of the American Medical Association. But critics say the study falls short of proving a direct cause between the number of gun laws and reduced gun violence.

As members of Congress prepare to vote on gun-control measures, the study also highlights the need for better evidence-based research to inform policymakers about which laws are most effective at curbing gun violence and why.

“Our motivation was really to understand what are the interventions that can be done to reduce firearm mortality," Eric Fleegler, the study's lead author and a pediatrician and researcher at Boston Children's Hospital, told the Associated Press.

The new study suggests – but doesn’t prove – that increasing the number of gun-control laws in states will result in fewer gun-related deaths.

The study ranked all 50 states based on the number of gun laws on the books, which fell under five broad categories: curb firearm trafficking, strengthen background checks, improve child safety, ban military-style assault weapons, and restrict guns in public places. The states were divided into four groups based on their legislative score, 0 to 28. Then the study applied gun-related death data from 2007 to 2010 provided by the Center for Disease Control and Prevention (CDC).

Overall, the states with the most laws had a 42 percent lower gun-death rate than states with the least number of laws.

The lowest gun-death rate was in Hawaii, with 3 deaths per 100,000 residents. Hawaii scored 16 on the legislative score. Louisiana ranked highest in the rate of gun deaths at 18 per 100,000 residents. It’s legislative score was 1.

“The study provides evidence that the laws may work,” says David Hemenway, a co-author and director of the Harvard Injury Control Research Center at the Harvard School of Public Health in Boston.

“The study provides evidence that in states with stronger laws and fewer gun deaths – that has a positive effect,” he adds.

But the research has limitations, which the study and critics identify: Just because the two factors are present, doesn’t mean that one caused the other.

“The real question is not about the number of firearm laws but whether the laws ultimately safeguard the citizens they are intended to protect,” the report said.

 For research that was intended to inform policymakers, the study offers no guidance, said Garen Wintemute, director the Violence Prevention Research Program at the University of California at Davis, in a video response to the study.

“Do the laws work, or not? If so, which ones?” Dr. Wintemute wrote in a commentary on the study. “Should policymakers enact the entire package? Some part? Which part?”

The study’s limited scope does not include a complete list of gun laws, and it fails to account for differences between states in specific laws. It doesn’t include measures for how hard states work to enforce their laws, nor does it evaluate the effect on the flow of firearms between states with different laws.

One of the main points that limits the study’s conclusions is the how the rate of gun ownership in states impacts the correlation of laws and gun deaths, said Wintemute.

States generally fall on to either end of the spectrum, either strong laws with fewer deaths or weak laws with more deaths.

This is a problem because the rate of gun ownership is associated with the rate of violent deaths, he said. And, “it’s easier to enact these laws in states that have a low rate of gun ownership to begin with.”

Because gun ownership is not as important in those states, there’s less opposition, he said. “We cannot say that these laws, individually or in aggregate, drive firearm death rates up or down.”

Both Wintemute and Dr. Hemenway agree that more funding is needed to do studies that further explore the links between legislation and reduced rates of gun violence.

“The larger problem is that we effectively stopped doing research on this problem 15 years ago,” Wintemute said. “And now, at a time when we really want to have the evidence on what works and why, we don’t have that evidence.”  

Since 1996, the CDC has been explicitly barred by Congress from researching the causes and prevention of gun violence as a public-health issue. Some conservative lawmakers believed that antigun researchers would politicize the data. In an executive order on Jan. 16, President Obama directed the CDC to study the best ways to reduce gun violence.

But researchers will have to wait to see if Congress goes on to appropriate funds for gun violence research.

“Until we revitalize firearm-violence research, studies using available data will often be the best we have,” Wintemute wrote. “They are not good enough.”