A new study from researchers at Stanford University debunks the oft-cited fact that more guns leads to less crime. In fact, the researchers found, the opposite is the case: right-to-carry laws are associated with higher rates of aggravated assault, rape, robbery and murder.
The results of the study are imperfect. Lead author of the study and Stanford law professor John J. Donohue III said, "Trying to estimate the impact of right-to-carry laws has been a vexing task over the last two decades." While they specifically found that right-to-carry laws had yielded 8 percent more instances of aggravated assault, that number isn't set in stone because of a number of confounding factors (such as various drug epidemics). Regardless, Donohue says that 8 percent is a low guess--the reality could be much higher.
Still, the study's findings are significant in that it pokes a hole in the gun lobby's main argument. The Washington Post's Christopher Ingraham provides context:
The notion stems from a paper published in 1997 by economists John Lott and David Mustard, who looked at county-level crime data from 1977 to 1992 and concluded that "allowing citizens to carry concealed weapons deters violent crimes and it appears to produce no increase in accidental deaths." Of course, the study of gun crime has advanced significantly since then (no thanks to Congress). Some researchers have gone so far as to call Lott and Mustard's original study "completely discredited."
One of the major critiques of the study came from the National Research Council, which in 2004 extended the data through the year 2000 and ultimately concluded that "with the current evidence it is not possible to determine that there is a causal link between the passage of right-to-carry laws and crime rates." Or in other words, "More guns, less crime? ¯\_(ツ)_/¯"
Daniel Webster, director of the Johns Hopkins Center for Gun Policy and Research, confirmed to the Huffington Post that the study accurately concluded that "right-to-carry laws increase firearm-related assaults," although "the exact magnitude of that effect is uncertain."