Drug Legalization by Modus Ponens

1)      If drug prohibition doesn’t reduce drug-related harms, we should legalize drugs.

2)      Drug prohibition doesn’t reduce drug-related harms.
3)      Therefore we should legalize drugs.

This simple argument is an example of modus ponens. State a conditional, then state that the condition is true, which implies that the consequent is true.

You can deny 1 and/or 2, but if you accept 1 and 2 there is no logical way to reject 3. In the debate over drug legalization, it might be fruitful to have skeptics of drug legalization state exactly which part of this argument they disagree with and why.

My guess is that most people who favor drug prohibition (“drug warriors”) reject 2. They believe that there would be a huge demand response if we legalized drugs, a lot more people would use the currently illegal drugs, and therefore we’d have a lot more drug-related social problems. As plausible as this story is at first blush, it falls apart when you scrutinize it in any detail. If someone is willing to pay the very high price of ruining their life with drug use, why would they be deterred by a legal penalty? And does anyone really think *total* intoxication would increase? If you legalized cocaine, it’s not as though all the new cocaine users would be people who were previously squeaky-clean. Presumably most of the new users would be people who are currently getting their high some other way, like drinking alcohol or perhaps using some other illegal drug. Legalization might change the mix of drugs that people are using, but it’s doubtful that it would change the overall amount of drug-induced intoxication. You’d likely see some new light users who will never use the high-concentration versions of these substances; there would be some coca tea drinkers (who presumably would then drink less caffeine) but very few crack smokers. When a new drug comes on the scene, you see a lot of “substitution”; people stop using one substance in lieu of another. But you don’t see many new users. (Example: states with legal or medical marijuana see less use of alcohol and lower rates of painkiller overdose deaths.)

Rejecting step 2 is very problematic. There are enough policy experiments to reject the notion that legalization (or any kind of liberalization) leads to a big demand response. And there is little evidence that a policy change of stricter drug prohibition leads to a decline in drug use. Drug warriors can at best claim that there is a modest demand response, but one that has been difficult to detect in any kind of historical data.

It seems silly, but some people reject step 1). It would seem that if drug prohibition fails in its primary objective, really its only sensible objective, we should declare it a failed policy and legalize. But I’ve seen a couple of different reasons for rejecting the conditional.

I was arguing with a very committed drug warrior once, and I was trying to have a discussion about drug-related harms and how prohibition makes the problem worse. He played the moral trump card: “Morality beats cost-benefit analysis every time in a civilized country.” I found this statement to be incredibly foolish. In no sense can you even paint drugs as “evil” without reference to drug-related harms. If cocaine didn’t cause behavioral or health issues, there would be no “evil” to discuss in the first place. And if those harms are exacerbated by prohibition (as they surely are), then the moral implications of drug prohibition are the opposite of the ones he had in mind. I think he was really saying, “I’m going to be thick-headed about this, and I won’t be reasoned with.” But it was an example of someone rejecting the conditional. With this person (and presumably he has company), I wouldn’t have gotten past step 1).

Just a general point of advice: don’t play the moral trump card. It’s a bad-faith move if you’re trying to have a real discussion. And if anyone has the right to play the moral trump card, it’s the person who *isn’t* advocating the initiation of violence.  

I’ve seen another reason for rejecting 1), which has to do with the other “benefits” of drug prohibition that aren’t related to drug-induced harms. Police supposedly know who is and who isn’t a criminal, and they can bust someone for drug possession a lot more easily than proving an assault or a burglary. All they have to do is spot the target individual and frisk him, find a pipe or some drugs, and arrest him for that offense. There are several obvious problems with this. For one, as a rationale this would seem to justify outlawing certain modes of dress or speech patterns, or frankly ethnicity. If the goal is to let the cops bust whoever they want, there are other ways to do it; it’s just that the moral outrage at such policies would be far more obvious. Also, keep in mind that the police often explicitly look for drugs even when they aren’t looking for other kinds of crimes (like assault, robbery, or other crimes that involve actual victims). They put a great deal of work into “proving” that someone is a drug dealer, and after an outrageous no-knock entry of their residence, it often comes to light that the evidence was flimsy in the first place. The drug war isn’t just a tool for arresting real criminals, similar to catching Al Capone for tax evasion. Police resources are being diverted to serve this one goal, and innocent people are getting caught in the crossfire.

Probably some other people reject 1) for reasons of bald self-interest. Associations of prosecutors, prison guards, police, and alcohol producers raise hell whenever there is talk of drug liberalization. It should be easy enough to see this special pleading for what it is. We should ignore this kind of blatantly selfish special-interest lobbying.  

I’m guessing there aren’t that many people who would really deny step 1). The real crux of the disagreement is step 2), so that’s probably where most of the discussion should be focused. Is there a big demand response? How big? Is the deterrent effect worth all the social costs of prohibition (black market violence, tainted drugs of wildly fluctuating dosage, blood-borne pathogens for IV drug users, alienation of minority communities to law enforcement, etc)? The drug warriors are on extremely shaky ground here. They have to justify all these prohibition-related social costs, in return for a completely speculative demand-response (reduction in drug use) that utterly fails to show up in the real world.   

A simple request. Suppose you don’t have the patience for all of this logical argument and policy analysis. If that’s the case, please do the decent thing and set your default position to “pro-legalization.” If you aren’t thinking through these issues, then you don’t in any meaningful sense have an opinion on the relevant policy questions. Many people incorrectly default to “status quo”, but that’s wrong. There is no sense granting a presumption in favor of existing policy, knowing that policy is wrong in so many ways at any given time. The default ought to be “favor the policy that doesn’t initiate violence against non-violent offenders.” I’m not trying to claim that initiating violence is always wrong, just that it requires justification. And for something you haven’t thought through for yourself, you should default to the position that violence *isn’t* justified. The alternative is “violence is justified until proven otherwise,” and I’m not sure anyone really wants to go there.