Robert VerBruggen argues persuasively that the disastrous rate of addiction and death caused by legal opioids challenges the liberal presumption that consumers always benefit from (relatively) free markets. “Them’s fightin’ words” to those energized by the struggle to protect individual liberty from the state’s meddling in private affairs. But nitpicking the evidence he adduces in his Liberty Forum essay to defend ideological purity is not an honest response. Indeed, the points where I might differ with VerBruggen on facts tend to reinforce, not undermine, his thesis.
Instead I will argue that although people’s failure to consistently make prudent decisions concerning dependence-inducing intoxicants extends beyond opioids, the psychoactive drugs collectively nonetheless belong to a small class of products that merit a carve-out from libertarian principles.
One can worry about slippery slopes and camels getting their noses into the tent, but not a lot of contortions are needed to distinguish crack from crackers, or meth from milk. Far greater contortions are required to talk oneself into believing that people can be relied upon to moderate successfully their consumption of powerful analgesics that interfere with the natural neurotransmitters in the brain.
I begin by extending two of VerBruggen’s theses to other drugs.
He observes that prohibition does more to suppress use than is generally realized. Consider Figure 1, which shows the prevalence of self-reported marijuana use (the drug for which we have the best data) at three time points: 1) In 1979, near the end of the Carter administration and its liberal attitudes toward marijuana, 2) In 1992, after 12 years of Reagan-Bush anti-drug policies, and 3) 2014, the most recent year for which data are available.
Figure 1: Millions of People Reporting Marijuana Use in the Household Survey, Broken Down by Number of Days of Use Reported in the Past Month
Prohibition’s effects on prices is equally evident. The first state-legal stores selling cannabis for non-medical use opened in Colorado and Washington state in 2014. Figure 2 shows an immediate and sharp fall in prices. Removing the risk of arrest freed firms to expand and exploit economies of scale and employ more efficient growing and processing technologies. Lower prices engender greater use; a typical empirical study finds that a 10 percent decline in price can drive up use by 5 percent.
Figure 2: Cost of Buying a Gram of Marijuana Legally in Washington State
Prohibition’s effect on cocaine and heroin prices cannot be tracked over time, since no modern jurisdiction has legalized their production, but it can be observed in cross-section. It costs about $75 to FedEx a one-kilogram package from Bogota, Colombia to New York City, but a kilogram of cocaine that sells for $1,000 to $2,000 in Colombia fetches about $15,000 in U.S. wholesale markets. That markup is not monopoly rents; the trafficking business is quite competitive. Rather, traffickers demand high compensation for the risks they run in transporting contraband cocaine. Pushing cocaine down through the domestic distribution chain is also costly, driving the price up to over $100 per gram ($100,000 per kilogram) at retail.
VerBruggen also argues that prohibition does not require following draconian or pig-headed policies. Again, that is clearly true. Critics of American prohibition often wistfully dream of implementing smart Dutch or Swiss policies without realizing that drugs are also prohibited there. The Netherlands has never even legalized the production or wholesale trade in cannabis, only its retail sale. That spared them a Washington-style price collapse and aggressive marketing of brands.
Arguing that prohibition has effects and could be improved is not the same as explaining why banning a drug can be good policy. I undertake that challenge next, with two caveats.
First, drugs differ and prohibition is not appropriate for all. Caffeine should remain legal, and I leave aside the special case of marijuana. (Colleagues and I have literally written a book on that topic.) Yet the category of drugs-other-than-marijuana is responsible for the vast majority of the crime, violence, corruption, imprisonment, overdose death, blood-borne disease, poverty, and other ills we associate with drug use. So my argument applies to most drug prohibitions and their consequences according to every metric besides number of users.
Second, I concede that prohibition harms many people, probably more than it helps. However, it harms most of them only modestly, whereas some whom it protects benefit enormously.
That point is best made with data. Ideally we’d be able to compare patterns of use under prohibition to patterns under legalization, but since no nation in the modern era has legalized hard drugs, we have to start with data concerning prohibition. The key observation is that although most people use drugs happily, most of the consumption by weight and value is due to the smaller number who have lost control of their use and been harmed by it. We approximate harmful use by meeting the medical criteria for dependence, since that diagnosis is predicated on users’ reporting difficulty in cutting back and using more than they intend, despite experiencing harmful consequences.
In 1994, Jim Anthony and colleagues published what is still one of the most widely-cited estimates of what proportions of people who ever try various drugs go on to become dependent. Based on data collected between 1990 and 1992 by the National Comorbidity Survey, their estimates for the three major “hard” drugs varied from 11.2 percent for stimulants (which includes methamphetamine but also weaker amphetamine-type-stimulants) to 23.1 percent for heroin. I’ll focus on the proportion for cocaine (16.7 percent) since cocaine was then the most widely used hard drug.
The 16.7 percent figure does not mean that at any given time five people are enjoying cocaine for every one that is harmed by its use. People who become dependent often suffer through 10 or 20 years of dependence, whereas most of those who do not become dependent use for much less than a decade, and often only quite briefly. So the proportion of days-of-use that pertains to people struggling with dependence is much greater than 16.7 percent.
We can get a sense of this with data from the contemporaneous 1990-1992 household survey question: “About how many times in your life have you used cocaine?” Both data sets come from general population surveys using similar methods and questions.
Table 1 shows that 60 percent of those who tried cocaine never used it more than 10 times; only 14 percent reported using 100 or more times in their life, which is a smaller proportion than Anthony et al. reported become dependent. Since it is hard to become dependent without using repeatedly, this suggests that most people who use frequently on a sustained basis become dependent, and most of them likely end up wishing they’d never tried cocaine.
Table 1: Extent of Lifetime Use among those Who Reported Ever Having Used Cocaine in the 1990-1992 National Household Surveys
The tobacco-control community often ignores those who have smoked on fewer than 100 occasions, counting someone as an ever-smoker only if they cross the threshold of 100 occasions. Following that principle for cocaine, the proportion who become dependent among people who ever truly used—as opposed to merely experimented with—cocaine would be high indeed.
These data do not let us calculate precisely the proportion of days-of-cocaine-use that brought harmless joy, but a series of (moderately strong) simplifications can yield a rough guess. Suppose that the 16.7 percent that Anthony et al. estimated became dependent were to include all those who used 200 or more times and half of those using between 50 and 199 times, and assign midpoints to all ranges (for example, those in the three-to-five-day category would be credited with four days of use) and 400 days for the category “200 or more.” That is likely conservative because some who become dependent use frequently for many years on end. Those assumptions would imply about three days of dependent use for every day of use without dependence. In other words, the odds for the average person who tries cocaine are an expectation of three days of misery per day of harmless fun.
Furthermore, these are survey data. Some cocaine users don’t answer surveys, some are homeless, and some are already dead, so surveys grossly undercount use. That undercount is likely most severe among the people with the worst patterns of use, so survey data probably paint an overly optimistic picture.
Thus a naïve interpretation of Anthony et al.’s “capture ratio” is that trying cocaine is like playing Russian roulette, with just one chance in six of disaster. But after recognizing that happy use is transitory and harmful use is long-lasting, the odds are effectively reversed. It is more akin to playing roulette with bullets in five of the pistol’s chambers, not one.
It’s fair to wonder if this self-destructive consumption pattern is peculiar to drugs that are prohibited. Perhaps only undisciplined people use prohibited substances, and legions of responsible potential users are waiting on the sidelines until the drug is legal. Perhaps.
Or legalization’s lower prices, greater availability, and more aggressive marketing might encourage an even greater proportion to escalate to frequent and problematic use.
Data cannot arbitrate between those two speculations given that there are no data on cocaine legalization, but the experience with marijuana liberalization depicted in Figure 1 is not encouraging. Between 1992 and 2014, the number of past-month users almost tripled from 7.9 million to 21.9 million, but the number using daily or nearly daily increased more than eightfold from 0.9 million to 7.8 million. Daily and near-daily use does not necessarily equate to dependence on marijuana, as it usually does for cocaine, but policy liberalization clearly brought a shift toward greater intensity of use, and high-intensity use is risky with hard drugs.
Let us return to the libertarian objection of the slippery slope—that is, admitting that consumers cannot be trusted to look after their own welfare regarding drug use might open the door to meddlesome government social engineering in other aspects of life. As I have tried to show, psychoactive drugs are distinctive in ways that merit exceptional treatment. After all, the case for free markets depends on consumers’ making good decisions. Making a decision is a cognitive process implemented by our brains, and neurotransmitters underpin all brain activity. They carry information across synapses by binding with neuroreceptors on the post-synaptic nerve cell’s membrane.
Put simply, psychoactive drugs mess with neurotransmission. Many mimic neurotransmitters. Some bind with, but do not activate, neuroreceptors, and so block the endogenous neurotransmitters’ activity. Others stimulate “reuptake,” clearing neurotransmitters from the synapse more quickly. These actions explain why drug intoxication impairs decisionmaking.
Other effects persist beyond intoxication. The body responds to abnormal flows of neurotransmitters with homeostatic compensation. Consider, for example, the phenomenon of needing greater doses of analgesics as tolerance develops to opioids’ artificial suppression of pain. That homeostatic response makes good evolutionary sense (and, for that matter, good sense to creationists who believe in intelligent design). Survival depends on being able to experience aversive reactions to dangerous things. Putting your hand on a stove top should hurt; if it didn’t, we’d never learn what’s good for us. So when the body notices that it isn’t feeling the usual amount of aversion to the usual insults, it up-modulates sensitivity to pain.
Tolerance isn’t limited to analgesia; it applies also to opioids’ triggering of euphoria. The reason addicts “chase the first high” is that they can never again feel quite as euphoric as they did before their pleasure circuits were down-modulated. Nor is tolerance limited to opioids; with many drugs, greater and greater doses are needed to achieve the same effects.
Some brain changes can be reversed in months. Overdose deaths are common in the week after release from prison because a former inmate has lost his or her tolerance to opioids’ suppression of breathing. Other effects persist for decades; certain cues can stimulate overwhelming cravings in people who are in recovery from crack addiction, even years after that drug was last used.
An obvious point is worth stressing: Long-term effects imply that taking drugs can powerfully alter behavior, and even subconscious control of physiological processes like breathing, long after every molecule of the drug has been expelled from the body. Taking these chemicals can quite literally alter the brain, the very organ that free market theory depends on people using to make good decisions.
All activity alters the brain. We couldn’t remember something unless there was some change somewhere in our brains. But drugs’ actions are more fundamental. A relatively modest number of neurotransmitters orchestrate the countless things a brain can do. Nature is frugal. It reuses the same neurotransmitters to implement a wide range of activities. Rejiggering response to a neurotransmitter isn’t like storing a fact or pruning neural connections to reinforce certain circuits, as with learning a skill. It is messing with the raw material that underpins large segments of cognition.
Most consumer goods do not enter the body. Food penetrates the alimentary canal, but it is digested before crossing into the bloodstream. And some things that get into our blood cannot cross the blood-brain barrier. That psychoactive drugs literally enter our brains and modify brain functioning makes them truly atypical among consumer goods; carving out an exception for them need not undermine general principles.
In particular, acknowledging that an important minority of consumers make tragically bad choices about products that directly alter the neurochemical infrastructure of decisionmaking does not imply that libertarian principles are invalid for conventional articles of commerce.
 There are no corresponding data for 1980. The household survey did not become annual until 1990.
 James C. Anthony, Lynn A. Warner, and Ronald C. Kessler, “Comparative Epidemiology of Dependence on Tobacco, Alcohol, Controlled Substances, and Inhalants: Basic Findings from the National Comorbidity Survey,” Experimental and Clinical Psychopharmacology 2:3 (1994), 244-268.