The “More Guns, Less Crime” Hypothesis is Officially Dead
Despite his own recent research showing Right to Carry laws have no impact on murder rates, pro-gun advocate John Lott continues to peddle disinformation
By: Devin Hughes
John Lott — author of the “More Guns, Less Crime'' hypothesis and a book by that name — recently released a paper finding that Right to Carry laws and Permitless Carry have no statistically significant impact on murder rates.
This is striking as Lott has previously published a substantial number of studies finding that such laws decrease murder rates and other violent crimes, and used that work to advocate for weakening gun laws in testimony in front of legislatures as well as in court cases.
Lott’s new paper is the latest in a long series of academic back and forths over the impact of weakening concealed carry laws on violent crime.
Previous research has reached a similar “no impact” conclusion over the past few decades, although a significant proportion of the research actually finds that weakening concealed carry laws increases violent crime.
What makes this paper noteworthy, though, is that Lott is the lead author. Further, despite authoring a new paper that finds no statistically significant data to support the theory that more guns result in less crime, Lott’s recent op-eds and interviews for public consumption have not changed to reflect his new data.
It is worth taking a step back here and looking at the historical context of this debate. From 1997-2021, 65 academic studies on concealed carry laws and their impact on violent crime have been published: 18 find a decrease, 21 find no effect (or mixed), and 26 find an increase.
Forty percent of studies find that loosening concealed carry laws has a detrimental effect on crime, which is a plurality. Only 28% find a beneficial impact, and of those, most are old papers with numerous methodological flaws that more modern research has corrected.
The publication of the National Research Council (NRC) report in 2005 marked a key turning point in the literature on concealed carry. After reviewing the existing literature (through 2003) and conducting their own statistical analysis, the panel concluded:
“The literature on right-to-carry laws summarized in this chapter has obtained conflicting estimates of their effects on crime. Estimation results have proven to be very sensitive to the precise specification used and time period examined. The initial model specification, when extended to new data, does not show evidence that passage of right-to-carry laws reduces crime. The estimated effects are highly sensitive to seemingly minor changes in the model specification and control variables. No link between right-to-carry laws and changes in crime is apparent in the raw data, even in the initial sample; it is only once numerous covariates are included that the negative results in the early data emerge. While the trend models show a reduction in the crime growth rate following the adoption of right-to-carry laws, these trend reductions occur long after law adoption, casting serious doubt on the proposition that the trend models estimated in the literature reflect effects of the law change. Finally, some of the point estimates are imprecise. Thus, the committee concludes that with the current evidence it is not possible to determine that there is a causal link between the passage of right-to-carry laws and crime rates.”
The NRC chapter on concealed carry laws stands out from the rest of the report in a number of aspects.
First, the findings on concealed carry had one dissenter out of a panel of sixteen academics. The lone dissenter argued that RTC laws might reduce murder. In their own summary, the remaining fifteen empaneled academics strongly disputed the conclusion of the lone dissenter. Second, the panel used their own regression analysis to analyze the effect of RTC laws, which was in stark contrast to the remainder of the report which operated as a broad literature review, tepidly weighing in on studies concerning gun violence and various policies. Third, perhaps in part because the fifteen academics employed regression analysis of their own, they were quite pessimistic about future research finding conclusive results if the same methodology was employed as in the existing literature.
Statistical best practices have significantly improved since the publication of the NRC Report in 2005. For example: earlier studies often did not use clustered standard errors; were significantly biased by the drug epidemic; failed to properly consider the problems with multicollinearity when choosing control variables; did not properly select appropriate criminal justice variables; and did not properly account for major structural flaws in underlying county-level data.
Given these facts and the NRC’s skepticism of the existing literature’s ability to identify the causal impact of concealed carry laws, it is useful to look separately at the modern academic literature since that 2005 report.
From 2005-2021, 35 studies were conducted on loosening concealed carry laws, five of which find a decrease, seven find no effect (or mixed), and 23 find an increase in crime.
In summary, 66% of the modern academic literature finds that loosening concealed carry laws has a detrimental effect on crime, while only 14% finds a beneficial impact.
Since 2021 (when GVPedia conducted our last literature review of Right to Carry laws), the academic evidence that weakening concealed carry standards increases violent crime has grown even stronger.
For example, a peer-reviewed study published in July found that more concealed carry permits lead to increases in gun homicides. GVPedia’s own study of Permitless Carry found that states with such laws see a 22% increase in gun homicide for the three years after the law’s passage, more than doubling the 10% increase for the country overall in the same time period.
Lott’s recent paper along with a growing mountain of evidence compiled by other scholars should change the narrative surrounding weakening concealed carry laws. The “more guns, less crime” hypothesis is dead, and should be treated as such.
The question for scholars to determine now is how large a deleterious impact weakening concealed carry laws has on public safety. Unfortunately, Lott’s public commentary and advocacy remains unmoved by changing evidence, even when he is the author of said evidence. Lawmakers at the national and state level, as well as the media and public more broadly, should heed the scientific data and change course on the weakening of America’s gun laws. Too many lives are at stake to do otherwise.
Devin Hughes is the President and Founder of GVPedia, a non-profit that provides access to gun violence prevention research and data.
Image of John Lott courtesy of GVPedia.