Brian Doherty on Connecticut's Background Check Law and Murder Rate

Last week this blog shared Dr. John Lott's thoughts on that new study in the American Journal of Public Health, that purports to show a 1995 tightening in Connecticut's gun permit laws led to a 40% reduction in gun homicides over the next decade.  Now Reason.com is out with a new article investigating that same study. Many gun ban advocates immediately touted the study's finding to bolster their cause, but Reason.com's  Brian Doherty discovers that the study may not actually deliver what is advertised.

Given the amazingly complicated set of causes and incentives feeding into any human decision—and every gun homicide is the result of a human decision—establishing that the change in background check laws that "led to" a reduction in gun homicides "caused" them (even in that one Connecticut case, much less concluding that such laws can be relied on to have that effect in other places and times) is likely beyond any final authoritative conclusion via the usual methods of the social sciences.

Doherty details five specific problems with the study:

1. How do we know that synthetic-Connecticut really is a good marker for real Connecticut? The weight of that point seems to be almost entirely a pure case of believing that "past performance guarantees future results." Without saying anything about why it was so or should be presumed to always be so, the authors note that in the past Rhode Island's gun homicide levels matched Connecticut's very closely.
2. To return to the "appear" mentioned above in "Permit-to-purchase laws...appear to reduce the availability of handguns to criminals," given that we are assuming that the law is having all sorts of powerful effects on behavior and outcomes, don't we need to know something about how extensively or effectively the laws are being enforced, and have some decent data or reasonable guesses to be sure that the law's existence almost certainly is preventing many, many gun purchases by murderers that would have occurred without the law?
3. The authors are sure their gun-related cause leads to a gun-related effect by noting that the effects on homicide rates they allege to have found are almost all in gun homicides, not in other homicides. Curiously to me, the synthetic-Connecticut used to compare the non-gun homicides is very different than the mostly-Rhode Island one used for gun homicides; it is mostly New Hampshire. That comparison seems to be apples-oranges, and one wonders what the results would have been if they'd used the same synthetic Connecticut for both comparisons.
4. The study traces changes from 1995 to 2005; when I asked the CDC to send me the raw data numbers that the study relied on, the CDC warned me that "the coding of mortality data changed significantly in 1999, so you may not be able to compare number of deaths and death rates from 1998 and before with data from 1999 and after." [UPDATE: In an email sent after this post went up, the CDC says that "the change in...coding has almost no effect on homicide or suicide unlike other causes of death." So this point seems to be of little relevance.]
5. The study stops looking for effects 10 years after the law went into effect. Why might that be? Six of the eight years since 2005 for which CDC had data show Connecticut with a higher real gun homicide rate than 2005, the year that the authors chose to stop. If they had gone out to 2006, the reduction in rates in real Connecticut from 1995 to 2006 is cut to 12 percent.

Doherty discusses each of the problems in more detail and does a great job of picking the study apart.  It's a good read.

Gun Ban Advocates Use Faulty Research to Push Gun Licensing

Representative Chris Van Hollen (D - MD) has introduced a new bill in Congress that would require states to enact handgun licensing schemes or face the loss of federal funding.  Van Hollen is using a new study by Daniel Webster and others from the Bloomberg funded Johns Hopkins "Center for Gun Policy and Research" as proof that such laws reduce crime committed with firearms.   From The Hill:

The Handgun Purchaser Licensing Act would zero in on handgun purchases, but exempt rifles and other types of firearms.

It is backed by a study from the Johns Hopkins Center for Gun Policy and Research that found handgun licenses dramatically reduce homicide rates.

“Of the thousands of Americans murdered every single year by firearms, nearly 90 percent of those deaths occur with a handgun,” Van Hollen said. “With mothers, fathers, sisters, brothers, and friends dying every day because of guns, there is no question that gun violence is tearing at the fabric of our communities."

In addition to Van Hollen, who is running for the Senate, three Connecticut Democrats back the handgun bill: Rep. Elizabeth Esty, Sen. Richard Blumenthal and Sen. Chris Murphy. Connecticut was the site of the Sandy Hook elementary school massacre in 2012.

Their bill would provide states with an incentive to strengthen their guns laws. States that follow through with the handgun regulations would receive federal funding to carry them out, while those that refused would risk losing money.

To qualify, states would have to implement laws that require prospective gun owners to apply for a firearms license from a local police station. They would be required to pass a background check, including submitting fingerprints and photographs.

Those who pass the background check would receive a firearms license that they must provide to purchase a handgun.

The Democrats say the handgun bill would help law enforcement officials weed out criminals and other people who are not allowed to purchase guns.

But Dr. John Lott points out Webster has cherry picked the data to support his conclusion:

Their results are also extremely sensitive to the last year that they pick.  While it is true that Connecticut’s firearm homicide rate fell by 40% from 1995 to 2005, it only fell by 16% between 1995 and 2006 and 12.5% between 1995 and 2010.  Meanwhile the drops for the US and the rest of the Northeast are much greater.  From 1995 and 2006, the firearm homicide rates for the US and the rest of the Northeast fell respectively by 27% and 22%.  From 1995 and 2010, the drops were 39% and 31%.  The longer samples show a relative increase in Connecticut’s firearm homicide rate whether Rudolph et al. had looked at one additional year or five additional years.

This is not the first time Webster has "cherry picked" data to support his preconceived conclusions.  He did the same thing in the Missouri study that was used with the Connecticut study to push the licensing scheme.

This is one more example that congress did the right thing prohibiting tax payer money to pay for research that pushes gun control.  Webster is a gun ban advocate and each of his studies start at the end he wants to achieve and then he finds the data to support those conclusions.

Gun Ban Researcher Daniel Webster: Lott's Scholarship Has Been Completely Discredited

With the weekend decision in Parker vs. District of Columbia, a lot is being written about concealed carry.  The Washington Post had a blog post yesterday titled More Guns, Less Crime? Not Exactly.  In the post, Emily Badger writes:

That prediction — Washington will be safer without the gun ban — stems from what's known as the "more guns, less crime" hypothesis. It argues that violent crime declines in places where more legal gun owners carry the weapons in public, both because those people are capable of self-defense, and because would-be criminals know they're out there. "More guns, less crime" has been an incredibly potent idea in local policy debates over gun laws. But is there evidence that it's true?  

The District, which is appealing the decision, isn't buying it.

The theory has largely been fueled by a deeply contested 1997 paper by economists John Lott and David Mustard, who concluded that "concealed handguns are the most cost-effective method of reducing crime thus far analyzed by economists." If states without concealed-carry laws had them back in 1992, Lott and Mustard calculated, that year they could have avoided hundreds of murders, thousands of rapes and tens of thousands of assaults.

In the next paragraph you get a sense of where that term "deeply contested" may have originated.  Badger went to Johns Hopkins University gun ban researcher Daniel Webster.  Webster was part of the Consortium for Risk-Based Firearm Policy that held a "summit" at UVA at the end of last year.  Webster is currently involved in a project of the Police Executive Research Forum funded by the U.S. Department of Justice where he is studying a City of Sacramento ordinance requiring purchasers of ammunition in the city to sign a log and leave a fingerprint at the time of purchase and what impact it may have had on reducing crime.

Webster told Badger:

"John Lott’s research was in my opinion very instrumental over decades in having more states pass laws to make it easier to get permits to carry concealed loaded guns, and to lessen the barriers for those permit holders to take guns in ever more places, whether it's bars, or places of worship, or schools," says Daniel Webster, the director of the Johns Hopkins Center for Gun Policy and Research. "It’s all based upon Lott’s scholarship that has been completely discredited."

In fact, the very study that Webster sited to Badger as proof that Lott's research on concealed carry is flawed was itself challenged in the research paper, Trust But Verify: Lessons for the Empirical Evaluation of Law and Policy.  The Abstract to that paper notes:

In a recent article, Aneja, Donohue and Zhang claim that they are unable to replicate the regressions published by the National Research Council in Chapter 6 of Firearms and Violence. They conclude that the NRC regressions must have been based on bad data supplied by John Lott. The implication is that earlier studies that found that right-to-carry laws reduced crime were flawed because of bad data. However, we can replicate the NRC results with Lott’s original data and with the data set used by the NRC. The earlier studies are not flawed by bad data.

But even more important. Webster's quote in the blog post that "My opinion is that I think there’s greater evidence that they probably have had some harmful impact" just doesn't hold up when you look at the numbers.  For instance, between 2006 and 2012, the number of firearms sold in Virginia increased 101% while crime committed with a firearm decreased 28%. Firearm related crime has dropped in Virginia for four consecutive years.  A VCU criminal justice researcher put it this way:

“This appears to be additional evidence that more guns don’t necessarily lead to more crime,” said Thomas R. Baker, an assistant professor at Virginia Commonwealth University’s L. Douglas Wilder School of Government and Public Affairs who specializes in research methods and criminology theory.

Those who question Lott's research usually are on the side of the argument that wants to place more restrictions on law abiding gun owners. So, why doesn't the media openly question the bias that a proponent of gun control may have in their research?