United States Firearms per Capita and Homicide Rates. No Correlation

Sources: Homicide rates are from the FBI UCR. Per Capita Firearm rates calculated from Census data and private firearms numbers calculated using the method pioneered by Newton and Zimring. It was extended by Gary Kleck in “Point Blank: Guns and Violence in America”.  The number is the cumulative addition of domestic manufacture and imports with the subtraction of exports.

A linchpin of the argument of those who favor a disarmed population is the assumption of “More Guns = More Crime”. It was succinctly stated as an assumption in a recent paper.  (one source is referenced) Psychopathy, Gun Carrying, and Firearm Violence:

Carrying guns increases the risk of injury and death…

This is a hotly disputed assumption. There are several papers which dispute the premise. If carrying guns does not increase the risk of injury and death, the pragmatic argument for strict restrictions on gun ownership and use collapses. There is some evidence, if guns are restricted in a draconian manner, homicides with guns may be reduced.  Overall homicides are not reduced. 

If the substitution of other methods results in the same or more homicides, or if firearms are used to prevent homicides as well as facilitate them, the argument to restrict gun ownership is not viable.

Long term data to test the premise is available. There is FBI data on illegal homicides rates in the United States from 1910. Homicides are the most reliable crime figure because there is a body and an investigation. There is fairly good data on the number of firearms which are privately owned in the United States. If More guns = More crime, an increase in per capita firearms ownership should be  correlated with the homicide rate.

The number of cartridge firearms in the USA has not been calculated for dates before 1945. This was before records were commonly available. Serial numbers on firearms were generally not required before 1968.  Firearms first sold to the military, then later sold as surplus, are not included in these numbers, nor are firearms made for personal use. Semi-automatic, bolt action, and single shot rifles, revolvers and semi-automatic pistols sold as military surplus could number as high as 19 million.

Similarly firearms imported extralegally, such as “bringbacks” from foreign wars or exported extralegally, such as a shotgun sent in pieces back to Tio Juan on his farm in Mexico, are excluded from these official numbers. The assumption is the military arms sold as surplus and the personally crafted firearms are offset by the destruction of firearms and loss of firearms to extralegal export.

When the per capita numbers of firearms from 1945 to 2023 are compared to the homicide rate from the same years, there is no  correlation.  The homicide numbers have been recently “adjusted” for 2004 to 2023. Using those numbers, the correlation coefficient is .0107. The previous non-adjusted numbers give a correlation coefficient of  -.0037. The correlation coefficient can vary from 1 to -1. 1 is a complete correlation. -1 is a reverse correlation. Small numbers near zero show there is no significant correlation.  The correlation coefficient, calculated online, shows there is no correlation at p

The lack of correlation is consistent with visual comparison of the graph. Homicide rates go up and down while the number of firearms per capita consistently increases, except for one year, at the end of World War two, when all manufacturing capability was going into the war effort.

A consistent increase in per capita firearms ownership is precisely what would be expected of a valuable manufactured commodity whose constant dollar price is dropping as improved manufacturing techniques reduce the cost of production. The constant dollar cost of ammunition dropped along with the cost of firearms. The cost of ammunition dropped 96% in constant dollars form 1910 to 2022. The cost of firearms dropped about 98% in constant dollars over roughly the same period.

The lack of correlation between the per capita number of firearms and the homicide rate is a strong indicator. More guns do not equal more homicides.

©2024 by Dean Weingarten: Permission to share is granted when this notice and link are included.

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