Research Summary: Using panel data from 188 large cities during 1980-1999, we examined the possible homicide promoting effects of "three-strikes" laws.
RESULTS indicated that cities in states with three-strikes laws experienced short-term increases in homicide rates of 13% to 14% and long-term increases of 16% to 24% compared with cities in states without the laws.
CONCLUSIONS: Our results emphasize the fact that rarely are the possible unintended negative consequences of policy directives considered and point to the need for policy makers to consider both intended and unintended consequences of policy directives before the directives are codified.