Whatever the merits of "Stand Your Ground" laws, they appear to increase homicides by at least 7%, reports NPR. It cites a Texas A&M study of the 23 states that have enacted "Stand Your Ground" laws since 2005. Researchers looked at the homicide rate in those states pre- and post-law, as well as the rates of non-Stand Your Ground states. It determined between 500 and 700 additional homicides take place annually as a result. "These laws lower the cost of using lethal force," says Mark Hoekstra, the economist behind the study. "Our study finds that, as a result, you get more of it. Homicides go up by 7% to 9% in states that pass the laws."
What the study didn't find was "evidence of any [crime] deterrence effect over that same time period." Hoekstra says his results don't necessarily prove that the law is a failure. "It could be that these are self-defense killings," he says. "On the other hand, the increase could be driven by an escalation of violence by criminals. Or it could be an escalation of violence in otherwise nonviolent situations." Because of the varying ways states classify shootings, analyzing whether, say, more criminals were appearing at the scene armed, proves tricky. But NPR concludes that "What Hoekstra's data suggest is that in real-life conflicts, both sides think of the other guy as the bad guy."