Economist Mark Gius has a new study in the journal Applied Economics Letters that bears on the gun control debate. Gius finds that permissive concealed carry laws (generally, “shall issue”) result in a lower rate of homicide involving firearms. Conversely, state-level assault weapons bans have no statistically significant effect on the homicide rate involving guns. This is the abstract:

The purpose of the present study is to determine the effects of state-level assault weapons bans and concealed weapons laws on state-level murder rates. 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. The results of this ￼￼￼study are consistent with some prior research in this area, most notably Lott and Mustard (1997).

The author explains how his study differs from some past analyses:

The present study differs from this prior research in several ways. First, data for the period 1980 to 2009 is examined; this is one of the longest time periods examined in any research on assault weapons bans or CCW laws. Second, the gun-related murder rate is used as the dependent variable. The use of this crime rate is important because most other studies looked at violent crime rates or homicide rates. Violent crime rate data is not disaggregated into gun-related violent crime and non-gun violent crime, and homicides include justifiable killings and state-sanctioned killings; hence, an analysis using these types of crime rates may result in spurious conclusions.

I don’t necessarily agree with this. If permissive concealed carry laws result in a lower rate of homicide involving firearms, it is because criminals are deterred from attacking you by the possibility that you might be armed. That deterrence would operate equally, if not more so, if the criminal contemplated attacking you with a knife or blunt object. As to assault weapon bans, on the other hand, if they had any effect at all, it presumably would show up in statistics on homicides involving firearms.

This is from the author’s conclusion:

The CCW dummy variable is significant and positive, but the assault weapons ban is insignificant. Given that the average gun-related murder rate over the period in question was 3.44, the results of the present study indicate that states with more restrictive CCW laws had gun-related murder rates that were 10% higher. In addition, the Federal assault weapons ban is significant and positive, indicating that murder rates were 19.3% higher when the Federal ban was in effect. These results corroborate the findings of Lott and Mustard (1997). These results suggest that, even after controlling for unobservable state and year fixed effects, limiting the ability to carry concealed weapons may cause murder rates to increase.

This finding will be welcomed by gun rights advocates. But then there is this:

There may, however, be other explanations for these results. Laws may be ineffective due to loopholes and exemptions. The most violent states may also have the toughest gun control measures. Further research is warranted in this area.

Indeed. States with major urban areas have historically had the most restrictive gun laws, precisely because they had the highest crime rates. I am not sure how this can be sorted out statistically, but one thing we can say for certain: liberalizing concealed carry laws does not lead to an increase in homicide, or in crime generally; if anything, the opposite. Given that the Constitution guarantees the right to bear arms, and many millions of Americans believe that their personal security is enhanced by being armed, there really is nothing to be said in favor of restrictive carry laws. On the other hand, banning “assault weapons,” whatever those are, is purely a feel-good measure that does no good whatsoever. This is hardly surprising, as only a tiny number of murders are committed with rifles of any kind.