A RAND Corporation analysis published Friday confirms that the state of American gun policy science is not good, NPR reports. RAND analyzed thousands of studies and found only 63 that establish a causal relationship between specific gun policies and outcomes such as reductions in homicide and suicide, leaving lawmakers without clear facts. The analysis is notable for its depth, if not for its overall finding. RAND spent two years and $1 million on the project, which also included a survey of gun policy experts and the construction of a research database on state gun laws. The federal government has spent much less on research into gun violence than on similarly lethal issues, such as motor vehicle crashes, liver disease and sepsis. “Most of the effects that we were looking for evidence on, we didn’t find any evidence,” says RAND’s Andrew Morral.
The study found no clear evidence regarding the effects of any gun policies on hunting and recreational gun use, or on officer-involved shootings, or on mass shootings or on the defensive use of guns by civilians. There is relatively strong evidence that policies meant to prevent children from getting access to firearms, such as laws that require guns to be stored unloaded, or in locked containers, reduce both suicide and unintentional injury and death. Previous work has found that places that require a permit for the purchase of a firearm do reduce violent crime. There is also some evidence that prohibitions against purchase by people who have been diagnosed with mental illness reduce violent crime, and that “stand your ground” laws, which allow citizens who feel threatened in public to use lethal force without retreating first, lead to an increase in violent crime.