In what will certainly be gun control advocates' new least favorite study, Quinnipiac University’s Mark Gius found not only that states with restrictive concealed weapons laws had higher gun-related murder rates, but that assault weapons bans had no significant impact on murder rates at the state level.
The study by economist Mark Gius, published in Applied Economics Letters, sought to “determine the effects of state-level assault weapons bans and concealed weapons laws on state murder rates,” using extensive data from a thirty-year period, 1980-2009. In the abstract for the study, Gius sums up the findings:
Using data for the period 1980 to 2009 and controlling for state and year fixed effects, the results of the present study suggest that states with restrictions on the carrying of concealed weapons had higher gun-related murder rates than other states. It was also found that assault weapons bans did not significantly affect murder rates at the state level. These results suggest that restrictive concealed weapons laws may cause an increase in gun-related murders at the state level.
Gius notes that these results are consistent with previous research, specifically citing the work by John R. Lott and David B. Mustard.