In response to my post on Michael Glassner’s anti-gun sentiments in his “Culture of Fear” book, my fellow sociologist Matt Loveland pointed me to an article by economist Mark Duggan called “More Guns, More Crime,” published in the Journal of Political Economy in October 2001 (volume 109, number 5, pages 1086-1114).

Duggan’s abstract reads:

This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual rates of gun ownership at both the state and the county levels during the past two decades. My findings demonstrate that changes in gun ownership are significantly positively related to changes in the homicide rate, with this relationship driven almost entirely by an impact of gun ownership on murders in which a gun is used. The effect of gun ownership on all other crime categories is much less marked. Recent reductions in the fraction of households owning a gun can explain one‐third of the differential decline in gun homicides relative to nongun homicides since 1993.

Having now looked into the Duggan paper, I have two responses:

(1) GUNS AND “CRIME” OR GUNS AND HOMICIDE? The title is “More Guns, More Crime” but Duggan’s strongest findings concern homicide. In fact, at both the state and county level, Duggan finds no relationship between changes in gun ownership and rates of robbery, assault, or rape. At the state level, he finds a small relationship to burglary and larceny (Tables 7), and at the county level to auto theft (Table 9).

So, to the extent that there are concerns, they should have to do with homicide. Not that this is a minor concern, but the fact that more guns do not necessarily lead to more robberies, assaults, or rapes seems an equally significant finding from this study, to me at least.

(2) CHANGES IN MAGAZINE SALES AS PROXIES FOR MORE/LESS GUNS? IF the findings of this study are valid, the more limited claim that more guns = more homicide is still dependent on the quality of Guns & Ammo circulation as a proxy for guns.

Because there are not national gun registries and surveys like the Gallup Poll and the General Social Survey do not have enough cases to do analyses at the state level (much less the county level), scholars have needed to use various proxies to estimate the number of guns in these localities. Duggan writes, “The main impediment to applied work in this area was the absence of a reliable measure of gun ownership that could be measured across geographic areas over time. . . . I argue that state- and county-level sales data for one of the nation’s largest gun magazines, Guns & Ammo, provide a much more accurate way to measure both the level and the change in gun ownership within an area” (p. 1087).

Duggan supports his use of Guns & Ammo as a proxy by including in his article an entire section showing that sales of Guns & Ammo are higher in areas that demographically resemble areas in which there is likely to be more gun ownership (areas that are more rural, less educated, more southern, etc.). He also shows a strong correlation between sales of Guns & Ammo and the number of gun shows in a state.

So, he makes a convincing argument about gun magazine sales as a proxy for gun ownership. But his argument about more guns = more crime is based not on a simple cross-sectional correlation, but on an analysis of CHANGE in gun ownership and CHANGE in crime rates.

So, the change in the circulation of Guns & Ammo in relation to changes in crime rates is what is at issue here. If Guns & Ammo circulation goes up, then homicide rates should go up, if G&A is a good proxy for guns and if more guns = more homicide. Duggan finds this to be the case.

Of course, in gun research nothing is quite as simple as it seems. According to John R. Lott, Jr., there are some peculiarities about Guns & Ammo that reduce its value as a proxy for guns, and especially for changes in gun ownership rates. In the 3^rd edition of his book, More Guns, Less Crime (University of Chicago Press, 2010), Lott makes two points: (a) other magazines – specially, Handguns Magazine and American Handgunner – have more of a focus on handguns than Guns & Ammo, which makes them better proxies for the types of guns which are involved in most crime, and (b) Guns & Ammo “was the only one of the top seven largest gun magazines that experienced a drop in sales during the 1990s” (p. 297). Lott also says that a vice president at Primedia told him that during the 1990s, from 5 to 20 percent of national sales of Guns & Ammo were purchased by the company and then given away free to dentists’ and doctors’ offices. AND that these free copies were not distributed randomly throughout the country, but were targeted to locations where Primedia thought gun purchases would be increasing, including “areas where they thought that crime rates were going up” (p. 298).

Lott provides a table in More Guns, Less Crime that shows that of 7 gun magazines (G&A, American Handgunner, Handguns, American Hunter, American Rifleman, and North American Hunter), only sales of Guns & Ammo shows a statistically significant positive relationship to homicide (using two-tailed t-tests, Table A7.1, p. 366).

But, wait, there is still more. In an unpublished paper with Florenz Plassman, Lott conducts his own analyses using Handguns Magazine as a proxy and making some statistical adjustments for the fact that in most counties there are very small number of homicides in any given year. The results of these analyses find – congruent with Duggan – no evidence for a correlation between guns and rapes or robberies. They DO find, however, that “counties with population of more than 100,000 persons provides some evidence that increases in the number of magazine sales [i.e., in guns] cause the number of murder to increase,” but that this relationship does not hold true for all counties (p. 22).

They speculate that the effect of guns on murders may differ for urban and rural areas, which seems to make sense on its face considering that in some rural counties as many as 90 percent of households own guns (according to James D. Wright’s essay, “Ten Essential Observations on Guns in America”).

INITIAL CONCLUSION: There are no simple answers when it comes to assessing the relationship between guns and crime. Anyone who says there is probably has a dog in the fight or horse in the race or a certain fish to fry. This blog entry considers just two of many, many very, very statistically complex scholarly publications that speak to the question of whether more guns equal more crime or less. In my next entry I will consider some of the lessons I take from my initial foray into this research.