Alex Robson's ignorance

You may recall how Alex Robson demonstrated his ignorance of basic statistics and of climate research. Now he has written an op-ed in Sydney's Daily Telegraph where he claims that there is no research at all that contradicts John Lott:

Laws for the concealed carrying of guns are present in some form or another in 48 US states, and serious research (most notably by Professor John Lott of the State University of New York) consistently demonstrates their deterrent effect.

Robson seems to be unaware that the National Academy of Sciences reviewed the research and conducted its own analysis and found:

There is no credible evidence that "right-to-carry" laws, which allow qualified adults to carry concealed handguns, either decrease or increase violent crime.

Being unaware of the NAS report is one thing, but Robson doesn't seem to know about any of the numerous papers that contradict Lott.

Like this:

Kovandzic, Marvell and Vieraitis. The Impact of "Shall-Issue" Concealed Handgun Laws on Violent Crime Rates: Evidence From Panel Data for Large Urban Cities Homicide Studies (2005)

And this:

Ayres and Donohue, Shooting Down the More Guns, Less Crime Hypothesis. Stanford Law Review (2003)

This too:

Ayres and Donohue, The Latest Misfires in Support of the "More Guns, Less Crime" Hypothesis Stanford Law Review (2003)

Not to mention this:

Hepburn, Miller, Azrael, and Hemenway. The Effect of Nondiscretionary Concealed Weapon Carrying Laws on Homicide. Journal of Trauma (2004)

And these guys:

Rubin and Dezhbakhsh, The Effect of Concealed Handgun Laws on Crime: Beyond the Dummy Variables. International Review of Law and Economics

And this:

Maltz and Targonski. A Note on the use of County-level UCR Data. Journal of Quantitative Criminology (2002)

There's this:

Ludwig. Concealed-gun-carrying Laws and Violent Crime: Evidence from State Panel Data. International Review of Law and Economics (1998)

Oh yes, this too:

Helland and Tabarrok, Using Placebo Laws to Test "More Guns, Less Crime"

As well as this:

Black and Nagin, Do Right-to-carry Laws Deter Violent Crime? Journal of Legal Studies (1998)

And hey, this too:

Kovandzic and Marvell, Right-to-carry Concealed Handguns and Violent Crime: Crime Control Through Gun Decontrol? Criminology & Public Policy (2003)

Plus this one:

Harrison, Kennison, and Macedon, Crime and Concealed Gun Laws: A Reconsideration unpublished

Another one that Robson missed is this paper:

Duggan, More Guns, More Crime. Journal of Political Economy (2001)

And he missed this as well:

Hood and Neeley, Packin' in the Hood?: Examining Assumptions of Concealed-Handgun Research. Social Science Quarterly (2000)

And this:

Goertzel, Myths of Murder and Multiple Regression. The Skeptical Inquirer (2002)

This as well:

Alschuler, Two Guns, Four Guns, Six Guns, More Guns: Does Arming the Public Reduce Crime? Valparaiso University Law Review (1997)

Another one that slipped through Robson's net:

McDowall, Loftin and Wiersema. Easing Concealed-Firearm Laws: Effects on Homicide in Three States Journal of Criminal Law and Criminology (1995)

There are tools on the Internet that allow you to search for stuff. I guess Robson didn't use them because he missed this paper:

Pridemore. A Cautionary Note on Using County-Level Crime and Homicide Data
Homicide Studies (2005)

As well as this one:

Webster, Vernick, Ludwig, and Lester. Flawed Gun Policy Research Could Endanger Public Safety. American Journal of Public Health (1997)

And this one:

Zimring and Hawkins,Concealed Handguns: The Counterfeit Deterrent. The Responsive Community (1997)

And this makes twenty:

Cook and Ludwig. Aiming for evidence-based gun policy Journal of Policy Analysis and Management (2006)

But apart from twenty papers (almost all of the ones on this topic that weren't written by Lott), research consistently agrees with Lott's theory.

More like this

Yes but John Lott still agrees with John Lott. He also has a study that shows all other people named John Lott agree with John Lott, but he did misplace the full survey data.

I agree with Professor Lott, too.

By Mary Rosh (not verified) on 27 Apr 2007 #permalink

Did any study statistically analyze perpetrators, not just "shrunk data"? By that I mean linking homicide with laws, or something similar.

Pffft....all science does is prove stuff.

"... all science does is prove stuff". This contrasts poorly with the moral clarity attainable by economists and luminaries published by the Murdoch press and worse still proving stuff, compared to just saying stuff, doesn't pay.

In the Maltz and Targonski paper and the Goertzel paper, can you please tell me exactly where these authors re-estimate Lott and Mustard's regressions and provide results which contradict Lott and Mustard?

By Alex Robson (not verified) on 28 Apr 2007 #permalink

Alex, neither paper re-estimates Lott nad Mustard's regressions.

Maltz and Targonski conclude that L&M's data is unsuitable to be used in those regressions:

>Until improved methods of imputing county-level crime data are developed, tested, and implemented, they should not be used, especially in policy studies.

Goertzel says:

>One might ask, why are we dealing with these medium sized counties instead of major population centers? This was my first clue to the fundamental flaw in Lott's argument. My first inclination was to graph the trends in America's largest cities, because that's where the homicide problem is most severe. I immediately discovered that none of these cities had a "shall issue" law. The "shall issue" laws were put into effect primarily in states with low population density. This meant that Lott's data did not meet the fundamental assumptions for a regression analysis. To work properly, multiple regression requires that the "shall issue" variable be normally distributed throughout the data set. The mathematical calculations used to "control" for spurious relationships can't work if there is not a sufficient range of variation in the key variables. This was the "smoking gun" hidden in Lott's mass of tables and sophisticated equations. At no point in the book did he acknowledge this fact. When I asked him about this, he shrugged it off. He didn't did not see it as a problem, since he "controlled" for population size.

"One might ask, why are we dealing with these medium sized counties instead of major population centers"

Indeed. The most salient thing about American murder stats is that they are hugely correlated with population density; not too surprising when you think of it.

Again, not too surprising that restrictive gun laws will therefore be more prevalent in densely populated areas.

A less salient fact is that the murder rate **per capita** is in fact less in the densely populated regions.

There is no credible evidence that "right-to-carry" laws, which allow qualified adults to carry concealed handguns, either decrease or increase violent crime.

So why is this illegal? If it doesn't increase violence or murder what's the logic from preventing people from having the means of defending themsleves?