A 2018 RAND Corporation review of existing research concluded that "there is moderate evidence that stand-your-ground laws may increase homicide rates and limited evidence that the laws increase firearm homicides in particular." In 2019, RAND authors published an update, writing "Since publication of RAND's report, at least four additional studies meeting RAND's standards of rigor have reinforced the finding that "stand your ground" laws increase homicides. None of them found that "stand your ground" laws deter violent crime. No rigorous study has yet determined whether "stand your ground" laws promote legitimate acts of self-defense.