Actually, empirical evidence suggests a sure fire way to dramatically lower gun homicides: repeal drug laws

Sticking my umbrella up to try to deflect the tsunami of specious, beside-the-point, hiding-the-cultural-imperialism-ball, insult-to-reason uses of empirical evidence on violence & gun control (emanating from those on both sides of the debate), I offered a couple of feeble blog posts (here and here) urging more thoughtful, grounded arguments that are mindful both of the limits of our knowledge and our duty, as citizens of a liberal democracy, to justify our policy positions on grounds free of the impulse to use law as an expressive weapon for denigrating cultural styles that differ from our own.

I’m not satisfied by my performance.

The problem isn’t that what I wrote will make no difference, have no effect, etc. If that were the decisive issue, why would I ever say anything? I’m not trying to change the world; I’m just trying to engage other curious and concerned citizens who also want to think about issues reflectively and form positions that they think are factually supportable and morally defensible. I’m trying to help them so they’ll help me back, since I’m by no means certain I’m right either.

No, the problem wasn’t the futility of what I said but the incompleteness. “Don’t look to statistics” — could be read as denigrating the utility of empirical inquiry in assessing public policy and as expressing a sort of nihilistic “who cares, nothing we can do!” attitude, both of which would deeply misrepresent how I feel about evidence-based policymaking generally & about using evidence to think about guns.

So to amend I will emend.

I now want to point out that in fact, while the empirical evidence on the relationship between gun control and homicide is (at this time at least) utterly inconclusive, there certainly are policies out there that we have very solid evidence to believe would reduce gun-related homicides very substantially.

The one at the top of the list, in my view, is to legalize recreational drugs such as marijuana and cocaine.

The theory behind this policy prescription is that illegal markets breed competition-driven violence among suppliers by offering the prospect of monopoly profits and by denying them lawful means for enforcing commercial obligations.

The evidence is ample. In addition to empirical studies of drug-law enforcement and crime rates, it includes the marked increase in homicide rates that attended alcohol prohibition and the subsequent, dramatic deline of it after repeal of the 18th Amendment.

Actually, it’s pretty interesting to look at homicide rates over a broader historical time frame than typically is brought into view by those who opportunistically crop the picture in one way or another to support their position for or against gun control.  What you see is that there is a pretty steady historical trend toward decline in the US punctuated by expected noisy interludes but also by what appear to be some genuine, and genuinely dramatic, jumps & declines.

One of the jumps appears to have occurred with the onset of prohibition and one of the declines with repeal of prohibition.  Social scientists doing their best to understand the evidence generally have concluded that that those are real shifts, and that they really were caused by prohibition and repeal.

Criminologists looking at the impact of drug prohibition can use the models developed in connection with alcohol prohibition and other modeling strategies to try to assess the impact of drug prohibition on crime. Obviously the evidence needs to be interpreted, supports reasonable competing interpretations, and can never do more than justify provisional conclusions, ones  that are necessarily subject to revision in light of new evidence, new analyses, and so forth.

But I’d say the weight of the evidence pretty convincingly shows that drug-related homicides generated as a consequence of drug prohibition are tremendously high and account for much of the difference in the homicide rates in the U.S. and those in comparable liberal market societies (the non-liberal, non-market societies all are burdened with homicide rates orders of magnitude higher; guns don’t explain that–  the pacifying influence of doux commerce does).  By all means decide for yourself, though; I’ve cited some reading material at the end of this post & urge others to call our attention to more in the comments section.

There are obviously other spikes & dips in the “secular” (as econometricians would say; here that’s a very nice adjective to use) downward trend in homicide in the U.S. E.g., the upsurge of homicides in the 1960s and the decline in the 1990s. Most of the gun-control combatants mine this period for support for their claims — they should, since the data are rich with support for specious inference.  Scholarly discussion here recognizes that the evidence on the contribution of guns to these jumps is utterly, hopelessly inconclusive.

There is a very interesting empirical study, though, by economist Jeffrey Miron, who concludes that the available evidence is consistent with the hypothesis that the difference in homicide rates in the US and in other liberal market societies is attributable to our drug prohibition policies. Gun availability in the US, according to this hypothesis, doesn’t directly account for the difference in homicide rates between the US and these countries; rather, gun availability mediates the impact between drug prohibition and homicide rates in the US, because the criminogenic properties of drug prohibition create both a demand for murder of one’s competitors and a demand for guns to use for that purpose.

One of the very nice things about Miron’s analysis, too, is that he is appropriately provisional about his conclusions:

The empirical results presented above provide a possible explanation for the large differences in violence rates across countries, and they suggest that previous analyses might have spuriously attributed these differences to gun control or availability. According to the analysis here, differences in drug prohibition enforcement explain differences in violence, which in turn explain differences in gun ownership that correlate positively with violence but do not cause that violence. Further, the results provide a hint that restrictive gun control regimes can themselves increase violence. As noted above, these results should be considered suggestive rather than conclusive. Future research on these issues will need to exploit time‐series rather than cross‐sectional data.

That’s what a real scholar sounds like, you see. In my view, it’s what an open-minded citizen sounds like too.

Now one thing to note: Obviously, decriminalizing marijuana and cocaine couldn’t be expected to prevent mass shootings like the one in Newtown, or Aurora, or Phoenix, or Columbine, etc. (Maybe there’d be fewer guns around, actually, if we didn’t have the demand for them associated with their contribution to the illegal drug trade, but there are already so many around — the gun & people populations are neck-and-neck — that I think disturbed people would still have no trouble getting their hands on them.)

But here’s another thing to note: these very sad incidents “represent only a sliver of America’s overall gun violence.” Those who are appropriately interested in reducing gun homicides generally and who are (also appropriately) making this tragedy the occasion to discuss how we as a society can and must do more to make our citizens safe, and who are, in the course of making their arguments invoking (appropraitely!) the overall gun homicide rate should be focusing on what we can be done most directly and feasibly to save the most lives.

Repealing drug laws would do more —  much, much, much more — than banning assault rifles (a measure I would agree is quite appropriate); barring carrying of concealed handguns in public  (I’d vote for that in my state, if after hearing from people who felt differently from me, I could give an account of my position that fairly meets their points and doesn’t trade on tacit hostility toward or mere incomprehension of  whatever contribution owning a gun makes to their experience of a meaningful free life); closing the “gun show” loophole; extending waiting periods etc.  Or at least there is evidence for believing that, and we are entitled to make policy on the best understanding we can form of how the world works so long as we are open to new evidence and aren’t otherwise interfering with liberties that we ought, in a liberal society, to respect.

…Now, what other policies might help? And in particular, if we are concerned about deaths of children?   Well, there’s swimming pools …. But I’ve said enough for now.


Barnett, R. & Trip, B. Drug Prohibition and the Weakness of Public Policy’(1994). Yale LJ 103, 2593.

Hirschman, A.O. The Passion and the Interests: Political Arguments for Capitalism Before Its Triumph. (1977).
Husak, D. Legalize This! The Case for Decriminalizing Drugs. (Verso, New York; 2002).

Jensen, G.F. Prohibition, Alcohol, and Murder Untangling Countervailing Mechanisms. Homicide Studies 4, 18-36 (2000).

Kleiman, M. Marijuana : costs of abuse, costs of control. (Greenwood Press, New York; 1989).

Kleiman, M., Caulkins, J.P. & Hawken, A. Drugs and drug policy : what everyone needs to know. (Oxford University Press, Oxford ; New York; 2011).

MacCoun, R.J. & Reuter, P. Drug war heresies : learning from other vices, times, and places. (Cambridge University Press, Cambridge, U.K. ; New York; 2001).

Miron, J.A. & Zwiebel, J. The Economic Case Against Drug Prohibition. The Journal of Economic Perspectives 9, 175-192 (1995).

Miron, J.A. Violence, Guns, and Drugs: A Cross‐Country Analysis*. Journal of Law and Economics 44, 615-633 (2001).

Pinker, S. The better angels of our nature : why violence has declined. (Viking, New York; 2011).

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