No, this is not some theoretical piece I’ve put together, but an actual article in the JOurnal of Public Economics, titled “The Social Cost of Gun Ownership.”

Here is the abstract:

This paper provides new estimates of the effect of household gun prevalence on homicide rates, and infers the marginal external cost of handgun ownership. The estimates utilize a superior proxy for gun prevalence, the percentage of suicides committed with a gun, which we validate. Using county- and state-level panels for 20 years, we estimate the elasticity of homicide with respect to gun prevalence as between +0.1 and + 0.3. All of the effect of gun prevalence is on gun homicide rates. Under certain reasonable assumptions, the average annual marginal social cost of household gun ownership is in the range $100 to $1800.

And from the intro:

Widespread gun ownership in a community could provide a general deterrent to criminal predation, lowering the risk to owners and non-owners alike. But widespread gun ownership could also lead to increased risks of various sorts, including the possibility that guns will be misused by the owners or transferred to dangerous people through theft or unregulated sale. Whether the social costs of gun ownership are positive or negative is arguably the most fundamental question for the regulation of firearms in the United States.

Notably, the paper makes no effort to define “social cost.”

In Judging the Constitutionality of Social Cost, I venture to give meaning to social cost–a term something that courts routinely toss around without ever bothering to define.

The Supreme Court has recognized two types of social cost, that I have labeled liberty costs and safety costs. First, liberty costs, refer to the risk of negative externalities to society as a whole that can result from individuals exercising liberty. Second, safety costs, refer to the risk of negative externalities to individual liberty that can result from the state providing for collective safety.

This article only considers the liberty costs (how owning a gun can harm others), but fails to consider the safety costs (how the government restricting access to gun can harm individual liberty). Both of these costs are very important.

H/T Tyler Cowen via @JustinWolfers