Latest Fox News piece: "Connecticut's strict gun licensing law linked to steep drop in homicides? Not really"

My newest piece at Fox News starts this way:

A new study in the American Journal of Public Health claims that the state of Connecticut’s 1995 gun licensing law has reduced firearm homicide rates by 40 percent.  But this just released study gives academics a bad name.  Not surprisingly, anti-gun activist and former New York City mayor Michael Bloomberg and the left-wing Joyce Foundation funded the research. 

The study cherry picks which states with gun licensing laws are examined, which years are looked at, and the type of crime to study. Any normal researcher would look at all the states in the country that have passed a similar law and compares the changes in crime trends between those states that passed the laws to those that didn’t. 

Sure, from 1995 to 2005 the firearm homicide rate in Connecticut did indeed fall from 3.13 to 1.88 per 100,000 people, a 40% drop over a ten-year period.  Not mentioned is that the firearms homicide rate was falling even faster immediately before the licensing law went into effect, falling from 4.5 to 3.13 per 100,000 residents -- more than a 30 percent drop in just two years. 

When researchers throw out data, there had better be a good reason.  They didn’t have one. They cite a paper that looked at the impact of smoking for 12 years after cigarette taxes were increased. What cigarettes have to do with explaining crime rates and what 12 years has to do with only looking at 10 years of data is never explained, though possibly they thought no one would actually read the paper they cited. 

In any case, their results change appreciably if just one more year is added to their data.  Between 1995 and 2006, Connecticut’s firearm homicide rate fell by just 16 percent.  By comparison, the rates for the U.S. and the rest of the Northeast fell respectively by 27 percent and 22 percent.  If Connecticut’s firearm homicide rate didn’t fall as much as the rest of the country, why should we think that the licensing law was so beneficial? 

Why the authors of the study chose to ignore other violent crimes also becomes clear pretty quickly. Relative to the rest of the United States, Connecticut’s overall violent crime rate as well as its robbery and aggravated assault rates were clearly falling prior to the prior to the 1995 law and rising afterwards.  Rape was unchanged. . . .

The rest of the piece is available here.