Scott Sumner  

The "War on Drugs" and crime rates

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Bryan Caplan has a new post discussing the impact of drug legalization on the overall crime rate.

In the absence of the War on Drugs, many non-drug offenses would never have been committed. Without prohibition, gang-related violence - and related weapons charges (subsumed under "Public-order" at the state level) - would plummet. Habit-related property crimes would probably do the same, albeit to a smaller degree. Theoretically, drug offenders might simply switch into other illegal activities once drugs were legal, but it's hard to believe this effect would be sizable.

My best guess: Five years after the end of the War on Drugs, half of the prison-years handed out for non-robbery violent crime would be gone, along with 20% of the prison-years for robbery and property crimes, and 75% of the prison-years for weapons charges. That's roughly half of all prison-years at the state level, and two-thirds of all prison-years at the federal level.

It's worth noting that when alcohol prohibition was repealed the murder rate in America fell by 40%:
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You may want to go to page 30 of the paper to see a larger version of the graph. A few points:
1. The actual decline might appear to be 50%, but the last 10% was an artificially low murder rate during WWII. So 40% is a better estimate.
2. Some of the decline might have been economic recovery after 1933 (when repeal occurred) but in absolute terms the economy was depressed throughout the 1930s, relative to the booming 1920s. And the murder rate was also very high during the 1920s.
3. On the other hand the murder rate did not seem to rise sharply under prohibition.
4. On the other, other hand there was a long-term downtrend in murder as the immigrant wave was "domesticated" between 1910 and 1950. It's reasonable to suppose that the murder rate normally would have declined significantly during the booming 1920s. If you draw a straight line between 1919 and 1950, it looks like prohibition was a big problem.

My best guess is that repeal of prohibition reduced murders by at least 25%. Would that happen today with drug legalization? Hard to say. If it had occurred when the murder rate was quite high in 1990, then the murder rate would have probably fallen sharply. Today it would fall, but perhaps less sharply. On the other hand there would be many, many fewer murder victims in Latin America. And I'm sure that Bryan (as well as liberals, conservative Christians, etc.) would also want us to take their welfare into account when making a decision.

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CATEGORIES: Economics of Crime

COMMENTS (13 to date)
ThomasH writes:

This seem quite plausible. If we are charitable it was a policy based on a faulty cost-benefit analysis. But as Robin Hanson might say, "drug policy is not about drugs." It was more likely about Republicans finding ways to lock up "undesirables," spreading a little pork to rural areas where prisons are located, and making Democrats look bad.

Christophe Biocca writes:

Thomas H:

It's not super historical to single out the elephants, when Harry J. Anslinger's initial push to ban marijuana occured in 1934-1937 under FDR (with his support).

The more appropriate outlook is to treat the War on Drugs as the extension of Prohibition's puritanism, but targeted at less popular (and hence easier to ban) vices. The fact that it targeted mostly "undesirables" was part and parcel of how it managed to survive when Prohibition didn't. Even today, all the victories on the legalization side are due to the increasing popularity of certain drugs.

Anslinger went from running the Bureau of Prohibition to becoming the first head of the Federal Bureau of Narcotics pretty much overnight.

John Hayes writes:

I don't think the prison population, especially federal would drop proportionate to drug offenders. In federal prison, drug crimes and weapons crimes are much easier to prosecute than other type of crimes. Any "possession" type crime relies almost entirely on police officer testimony that is hard to impeach.

Sometimes this is to the deficit of the citizen, because it's easy, sometimes it's to the credit, because it's a plea bargain to avoid a considerably worse sentence for the purpose of efficiency, sometimes there are collaboration credits. Lets call this a pricing process.

In general, looking at convictions is not that useful a measure of actual incidences of crime because that's the tail end of an elaborate, complex incentive, sausage making plea process. Never reason from a prison population change.

ChrisA writes:

I think international comparisons might be useful here. I don't think that the US has a particularly harsh anti-drug legislation compared with most of Europe say. Yes the incarceration rate in the US is much higher than there. So the cause of the high incarceration rate in the US cannot be mostly due to draconian drug laws.

John B writes:

I've read that a large part of the drop in the murder rate this decade is due to improvements in our ability to handle trauma. Many gun-shot victims who would have died in 1974 survive in 2014 and so are not counted as murder victims.

While improvement has been happening faster recently, the post-Prohibition era wasn't without medical progress, so some of the drop in the murder rate then might have been due to medical progress. X-rays and sulfa drugs would have been becoming more widely used then, for example.

Scott Sumner writes:

John Hayes, You said.

"Never reason from a prison population change."

That's right, and over at Vox there is a good example of that fallacy.

John B. That's part of it, but the plunge after 1933 was sudden and very steep. So it's not just medical progress.

KPres writes:

The dominant social conservativism of the post-war era should get more credit than it does, not that I'd expect that on a libertarian blog. Since social conservativism stresses controlling your passions, it's no surprise you'd see a decline in the murder rate, followed by a steep rise as the free-spirited, libertine cultural norms of the 60s took root.

Bruce Cleaver writes:

"On the other, other hand there was a long-term downtrend in murder as the immigrant wave was "domesticated" between 1910 and 1950. "

What, exactly, are you saying here? The immigrant wave produced more murders than the rest of the population initially (and this later subsided)? Something else?

Nathan W writes:

I don't think Thomas' point is relevant for the 1930s (since the legal framework was basically being built behind the scenes, as far as I understand), but it very much seems to me that, through the 1950s-present, this enters into the appeal to some types of people with excessive needs to prop themselves two notches higher than their peers who aren't puritan enough, and what's more reaffirming of your superiority than the ability to imprison others for their inferior choices?

At the end of the day, my guess is that suburbanization is a far greater threat to American economic potential than drugs which have been classified as illicit, but then again those suburbs offer a way for those same folks to keep themselves clean from contact with their lesser brethren.

Not saying it's exactly like that, but I think about 10-50% like that in most cases of people with strong anti-drug opinions. Also, borderline brainwashing, or at least facts-poor propaganda, goes pretty far in explaining this.

Mr. Econotarian writes:

LA's homicide rate was maximum was 1,092 homicides in 1992. Last year it was 298. Keep in mind that marijuana is basically legal here - the medical requirement is a minimal barrier.

Jacob A. Geller writes:

Would it be possible to tease out the effect of Prohibition (or the War on Drugs) on homicide rates by using temporal or spacial variation in enforcement?

That would probably present a wicked endogeneity problem, but it might be worth a crack...


NZ writes:

@Christophe Biacca:

Treating the War on Drugs as an extension of Prohibition's puritanism isn't quite appropriate either. The underpinnings weren't about puritanism per se.

Rather, they were more closely tied with a kind of New World Order mentality that also involved feminism, globalism, and quasi-Marxist/authoritarian incarnations of equality enforcement.

Progressives were the enthusiastic carriers of this mentality up until after WWII, when many of them defected as Neocons. (Conservatives shrugged complacently, not considering drugs a serious issue up to that point, and this allowed the Progressives to go forward unfettered.) In the postwar period, Neocons took the marketing of the drugs issue with them (and later employed it as part of the Southern Strategy). Still, the Left remained quietly dedicated to it as well:

For example, Joe Biden was instrumental in adding civil asset forfeiture to the core toolbelt of drug warriors. President Obama's statements against the drug war turned out to be spurious. And his wife has basically been porting the drug war template over to the arena of junk food.

Globalism is the big one there. If you read about the Shanghai and Geneva opium conferences and how those got started, it becomes clear that the underlying intent was to find a way to make the US relevant in the non-Western world. During WWII, we withheld support of allies until they promised to comply with international drug policy. Then there was the CIA selling drugs in Afghanistan and South America. And now today we invent enemies in the Middle East to fight and make sure they stay funded with heroin prices inflated by prohibition. Muslim terrorists are starting to collude with Central American drug gangs, but this hasn't been a big news item, largely because it's part of the plan.

Scott Sumner writes:

Kpres, My hunch is that crime rose in the 1960s and early 1970s because of much lower prison sentences, as well as the war on drugs.

Bruce, Yes, more initially---then later it subsided as they moved out of poverty.

Jacob, Check out this study:

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