But it's actually a wide-ranging debate/discussion of drugs and drug policy, not necessarily aimed specifically at answering this question. (The debate was a tie by the official vote, which surprised me. Sullum clearly had the better arguments and the facts on his side. Perhaps he would have won if the proposal was milder? The vote would have been more favorable to him if the proposal had been for a relaxation of drug laws or abolition of laws against particular drugs. I could actually see myself being a stickler for the literal language of the proposition and voting for Berenson, thinking, "Well, Sullum is right about prohibition generally, but he didn't defend this proposition.")Except for laws prohibiting the sale of drugs to minors and driving while impaired, all laws that penalize drug production, distribution, possession, and use should be abolished, along with special "sin" taxes on drugs.
I will try to discuss the major themes of the debate in the paragraphs below. The format of the debate was two 15-minute intros, two 5-minute responses, a Q&A session between the two participants and with the audience, and finally a 5-minute closing remarks, followed by the vote. I will try to integrate the discussion, in which a particular topic may have been discussed several minutes or an hour apart on the actual timeline (as one participant responds to the other several minutes later when it's their turn to speak, or when an audience member brings up a topic discussed an hour ago). I won't hesitate to add my own commentary or judgment. (It's my blog, anyway.)
Berenson repeatedly claims that drug use is a "crime of risk," similar to driving drunk or texting while driving. His point is that you are potentially causing random harm by taking drugs, so we need to punish all users, even the ones who don't happen to cause any harm. He says, "You can drive 50 miles drunk, but get pulled over a few feet from your house." The point being that even though you in fact made it home okay, you were risking people's lives along the entire way. I think he's trying to say that taking drugs is like playing a game of Russian Roulette (though, and I think he'd admit this, you'd have to have a gun with dozens or hundreds of chambers and load some less lethal bullets to make that analogy work). When someone uses drugs, it's like they cast some dice in a cosmic game of chance, and they get harmed very badly if it comes up snake-eyes.
I think this "random risk" framing is absolute bunk, and I've said so before. Initiating drug use and continuing to use is a choice, at least initially. Contrary to some of the scary claims made to fool school children and impressionable adults, a single dose cannot cause addiction. Certainly it won't cause a physical dependence. That requires a pattern of repeated drug use over time, which (again, at least initially) is a deliberate action. Let me start with a hypothetical scenario in which Berenson's framing is right. Suppose some random fraction of the population had a gene that made their brain chemistry interact badly with cocaine (or some other drug), such that those people are driven violently psychotic after a single dose. It might make sense to call that a "crime of risk," because taking drugs in that world more closely resembles a game of chance, unless we have some way of knowing who does and doesn't have the gene. But Berenson's framing does not match the real world. People have agency. Some fraction (a small fraction) of drug users become addicts and engage in compulsive, repeated drug use. While it's technically true that they would never become an addict if they never took that first dose, it's a harder sell to claim that that first dose causes their addiction. Sure, it's a first link in a causal chain. It's a necessary condition. But one has to account for the vast majority of users who don't develop problems. It simply isn't useful to abstract away people's agency (the thing that makes them human beings!) and treat their behaviors as "risks" that "cause" their other behaviors. What about a compelling video game? Or a significant other with toxic personality traits? Some fraction of people get addicted to gaming in ways that damage their lives, and some people find themselves unable to leave an unhealthy relationship. Is reading subversive literature a "crime of risk" because some fraction of people who do it will engage in violence? In such cases of political radicalization, it really is the literature that causes the person to become violent. It's far more useful to think of these behaviors as the willful actions of goal-directed, intelligent people, not random bit-flips in a robot whose machinery has been compromised.
(For an example of deliberate decision-making in drug addicts, see for example Carl Hart's research on crack addicts. He found that crack addicts were able to easily resist a free dose of crack if they were offered some other prize, such as a few dollars in cash or a gift card.)
Berenson has another major theme. He repeatedly says, "The pharmacological effects of drugs are the same whether they are legal or not." This is an incredibly weaselly kind of statement. It is literally true and utterly misleading at the same time. Yes, if someone is holding a syringe containing a dose of heroin, and suddenly the Supreme Court strikes down drug laws as unconstitutional (for once fulfilling their long-neglected constitutional duty), that dose of heroin will have the same pharmacological effects whether it's injected a moment before or a moment after the court's decision. So the statement is literally true. But it is a useless statement, because the legal status determines the distribution of drugs that are sold on the market. A harshly enforced drug war means that heroin and fentanyl will be preferred by dealers and traffickers. It's easier to hide and smuggle a single vial of fentanyl or carfentanyl than it is to traffic the equivalent dosage of heroin. And it's easier to smuggle pure heroin than it is to traffic large quantities of pain pills. Drug users prefer a user-friendly dose, while traffickers prefer to minimize (optimize anyway) their legal risks and maximize the number of effective doses per shipment. This is the classic observation that people prefer to drink beer and wine, but most alcohol produced during prohibition was hard liquor. It's not so much that the drug users' preferences change, nor is it true that distributors decide what users will consume and the user just has to accept it. It's rather that the economics change under prohibition. Traffickers could still ship beer during prohibition, but at a price that consumer aren't willing to pay.
Berenson apparently doesn't understand this. He implausibly insists that drug potency is driven by consumer demand. I think this is a rather pathetic dodge. He even acknowledges that alcohol prohibition caused distributors to specialized in more potent spirits, but insists that alcohol is somehow different. His explanation is that alcohol is "bulky", being dosed by the ounce, while other substances are dosed by the gram or milligram. This is irrelevant. Law enforcement routinely make seizures of many hundreds of pounds or even tons of cocaine or heroin. Traffickers certainly want to reduce the bulk of those shipments to reduce the chances of seizure, or to increase the bang-for-the-buck for a given size shipment. Fentanyl is about thirty times as potent as heroin by weight, so a one ton shipment of heroin can be reduced down to something that fits into a suitcase. (Alternatively but less plausibly, that one ton shipment can be made thirty times as profitable by trafficking in the more potent version of the drug.) The substitution of fentanyl for heroin is definitely driven by supply-side considerations and not by consumer demand. (There seems to be some debate about whether heroin users don't really want fentanyl at all or whether some of them have learned to use it carefully and thus prefer it. But it's clear that most of them would rather have heroin.) I feel obligated to call this stuff out whenever I see it, because Berenson is obviously wrong. Drug prohibitionists surely want to deny their responsibility for the carnage they've caused, and Berenson certainly tries to deflect blame here. But the huge spike in heroin and fentanyl deaths is 100% the fault of prohibitionists like Berenson. It is the absolutely predictable result of prohibition, which causes high and uncertain potency in the drug supply. That problem does not exist in the legal market, where alcohol and pharmaceuticals are clearly labeled. I think adults are morally responsible for the predictable consequences of the policies they advocate, and it's important to not allow them to wriggle out of their culpability. I have a hard time taking Berenson seriously here.
More important than potency is the reliability and predictability of the dosing. If drug users knew the exact dosage of whatever they were using, it wouldn't actually matter at all whether it was fentanyl or heroin. Professional pharmaceutical labs could measure out some particular dose of heroin or some equivalent dose of fentanyl. It's not the potency of fentanyl that makes it dangerous. In fact it's not inherently dangerous. The fentanyl patch is incredibly effective medicine, because it metes out a safe dose of the drug over time. The sheer potency of the drug itself is not relevant. It's the combination of high potency and imprecise dosing that makes it so dangerous. I believe Sullum points out that with alcohol, you know what you're getting because it's right there on the label. That becomes less true when we're dealing with a black market, where the traffickers are often amateurs and the products aren't meaningfully labeled.
Berenson points out that the "iron law of prohibition", that prohibition tends to increase potency, does not seem to apply to marijuana. I've dealt with that claim in a previous post. It appears to be true, but that doesn't mean that the "iron law" didn't apply to alcohol or doesn't apply to cocaine, heroin, and fentanyl. It makes sense to me that a marijuana supply that is constantly being disrupted by law enforcement won't be able to consistently produce high quality, high-dose strains of cannabis. Shutting down a grow operation is likely to destroy the institutional expertise that created that strain, and that knowledge is unlikely to be preserved and passed on. This is somewhat speculative; I don't know exactly why the economics of weed prohibition are different from the economics of heroin prohibition. But there is little doubt that traffickers prefer less bulky product, all things considered.
In another example of missing the point, Berenson responds to Sullum's long list of violent or corrupt actions by police officers. In his opening speech, Sullum mentions instances of drug dealers or innocent people being killed or injured by police raids. He also mentions several instances of corruption by drug cops. Berenson responds by claiming that Sullum is creating a distraction by focusing your attention on "an unfortunate few" police crimes. He's trying to cast these as isolated incidents committed by a few bad apples. Sullum's actual point is that drug law enforcement is inherently violent and corrupting of our institutions. Many of the violent actions by police officers aren't actually mistakes. They intentionally burst into residences where they think drug trafficking is taking place, often intentionally killing the dog or holding the family, often including children, at gunpoint while ransacking the house. Sullum doesn't make the following argument (unless I missed it), but drug policing intrinsically requires subterfuge and underhanded methods, because (unlike crimes with a victim) neither the seller nor the buyer is interested in cooperating with police. Police must rely on informants, who are often themselves criminals, whose criminal activities are known to and overlooked by police. Sometimes these informants are explicitly granted legal privileges in order to catch and prosecute drug traffickers who commit exactly the same offenses. As Sullum points out, some of these informants don't actually exist. (Ahem, Fuzzy Dunlop. Yes, it's fiction, but it happens in real life, too.) As the book Smoke and Mirrors by Dan Baum chronicles in great detail, drug policing has eroded our constitutional rights. Courts repeatedly ruled in favor of plainly unconstitutional searches and police surveillance, because for whatever reason they found drug enforcement so compelling. There are enormous constitutional carve-outs made explicitly in the "service" of making drug policing more feasible. This is clearly a consequence of trying to persecute a voluntary activity. Berenson's response to Sullum on this point is far too dismissive.
The beginning of Berenson's opening statement is rather bizarre. He explains that legalizers have been making the same arguments for decades, at one point saying that Sullum's speech could have been made 30 years ago. Legalizers have repeatedly made these same arguments as events have been unfolding to refute them, in Berenson's telling. He bemoans that drug warriors have been focusing on tactical battles without bothering to publicly explain why prohibition is a good idea. He says that prohibitionists have conceded the philosophical high ground to the legalizers. Supposedly the successful stigmatization of drunk driving, smoking, and pregnant drinking demonstrate the wrong-ness of legalization arguments. He points to the recent opioid crisis as an example of expanded access to recreational drugs leading to social harms, basically repeating (or implying without clearly stating) the standard narrative of the opioid epidemic. I've argued against that narrative in great detail on this blog, so I won't rehash it here. When Sullum gets a chance to respond, he points out that stigmatization is not prohibition! With the exception of drunk driving, the problems Berenson mentions were entirely a result of changing perceptions and norms. Population levels of smoking or pregnant drinking have fallen because of better information about risk and changing attitudes. I think Berenson is responding to a certain attitude among some legalizers who think there should be no stigma whatsoever regarding drug use. I'm sure some people hold this view. The libertarian position is that drugs should be legal, but private individuals can hold whatever beliefs or moral judgments they like about other people's hobbies and lifestyles. (I think Sullum shares this view, though I don't recall him saying so during the debate.) Anyway, this nice diversion actually makes a very libertarian point, which is that you don't need prohibition to massively change people's attitudes or behaviors regarding risk. I want to tell Berenson that prohibitionists have not "conceded" the philosophical high ground. Legalizers have taken it from them.
Berenson points out that legalizers have successfully framed the conversation to be about drug users, rather than the people around them who are hurt by the bad behavior of those users. He highlights a legitimate worry. There are certainly adults who use drugs and neglect their children or poison their relationships with other family members. Three point here in response. One, I don't think anyone has been allowed to forget about "the children." Helen Lovejoy political economy utterly dominates our politics. Two, I think Berenson would be hard pressed to find a penalty that deters drug users without harming their children. Penalties for drug use usually entail time in jail or humiliating drug court protocols. Any such penalty would make it hard to find steady work, and a drug conviction on your record is huge red flag to employers. Berenson seems hip to decriminalization, so maybe he's thinking we'd mostly avoid legal penalties for the users themselves. But there is no way to deter drug use without some kind of unpleasant penalty being applied to the user. Maybe we publicly cane drug users, then send them home and back to work? I think Berenson just hasn't thought this through. By the way, someone who is neglectful or abusive of their children is probably going to be non-responsive to the small risk of facing legal penalties for drug use. Three, alcohol. Alcoholics often neglect or abuse their family members, and it's legal. And that's a good segue to the alcohol discussion.
After both opening statements, Sullum responds to Berenson by saying that everything he says about the harms of "drugs" applies equally or even more intensely to alcohol. I think this is a really awkward point for prohibitionists, and no one has adequately answered it. Some just shrug their shoulders and say "Well, we're stuck with alcohol." Sometimes they argue (implausibly) that rates of heroin and cocaine use would be comparable to alcohol if we legalized these other substances, and the social harm from these drugs would grow in proportion. Berenson does a version of this. He attempted to claim that alcohol is less dangerous than the illegal drugs, saying "the reason there are so many harms related to alcohol is that so many people use alcohol." This isn't as straightforward as he implies; some 97 million people used opioids in 2015, with the vast majority of that use being medical. Certainly fewer users than alcohol, but the same order of magnitude. While I think it's a myth that recreational opioids were readily available over the past couple of decades, if Berenson believes this story he's got a mystery to explain: Why so few addicts? Why no increase in addiction or abuse rates?
Sullum challenges Berenson on the addictive potential of opioids, claiming the vast majority of medical users don't develop any kind of problem (which is certainly true). Berensons claims that if you gave everybody in the room a course of opioids, some would get addicted. Sullum conducts an impromptu poll of the audience, first asking how many had used prescription painkillers (which got a very large show of hands) and then asking how many had some kind of problem after their prescription ran out. Out of the huge number of people raising their hands to the first question, only a single person raised their hand to this second question. Not exactly a scientific poll, but 1) Berenson brought up the scenario of "giving everyone this room a course of opioids" and 2) Sullum has the relevant population-level statistics handy.
Sullum and Berenson converse about the relative dangers of alcohol and other drugs, with Sullum listing off some statistics on addiction rates per active user. He points out that the rate of addiction for prescription opioids per user (about 2%) is well below the rate for alcohol drinkers (~8%). Meth is slightly less addictive by the same measure. He concedes that cocaine and heroin are more addictive than alcohol (though not, in the case of cocaine, by a large margin). He points out that the substance that absolutely tops the list is tobacco. I think it's perfectly fair to point out that legal substances are more addictive and more damaging than illegal ones. Sullum also points out that it's not really addiction per se that we should be worried about. It's the harms from drug use that should concern us. Opioids don't do any kind of cumulative damage to the body, whereas alcohol damages the liver and tobacco damages the lungs (among other organ systems). Someone could be an opioid addict for decades and not suffer any harms from it. The only real danger is overdose and communicable diseases in the case of IV drug use, problems made much worse under prohibition. So contra Berenson, the legal recreational drugs are more harmful than at least some of the illegal ones. (Some illegal stimulants, like cocaine and meth, cause heart damage with excessive use. But Bolivian Indians chew coca leaf, and school children can ADHD medications, which are basically analogs of meth, around the clock for years, all without damage or escalation of use. So clearly the substances themselves can't be blamed. Other illegal drugs, like many hallucinogens and dissociative anastetics, are almost completely non-toxic.) I think Sullum is on solid ground in claiming that drug laws are arbitrary, meaning (as he clarifies) that legal status doesn't correlate with health risks or social problems. Berenson challenges his use of the term "arbitrary", but I think Sullum does an excellent job of defending his framing.
There is an interesting exchange about stoned versus drunk driving. Sullum points out that there might be some substitution away from alcohol and toward cannabis. Given that stoned driving doesn't seem to be as dangerous as drunk driving, the public health consequences of cannabis use might be a plus. Berenson is having none of this; he insists that stoned driving is just as dangerous as drunk driving, and cites some statistics about positive tests for cannabis among motorists in states that have legalized. Sullum points out that those studies don't actually distinguish between a mere positive test for cannabis metabolites and active impairment, because cannabis metabolites tend to stay in your system for a long time. Berenson insists that you can distinguish between active and passive metabolites. I had heard that this was not true, though admittedly my source was probably a Sullum piece at Reason. Sullum points out that he did a lot of research on this and actually spoke with the experts, many of whom are concerned about stoned driving, and that they tend to agree that there just isn't a universal threshold for impairment with THC (as there arguably is with the alcohol). He wrote a feature piece (I presume this one) based on his findings. Sullum mentions controlled trials on driving courses, where impairment is measured in a very scientific manor, and contrasts these with population-level trends in accidents, which are multi-factorial and it's hard to tease out causation (and thus blame cannabis legalization). Interestingly, Berenson later confronts a question about declining violence in a time of drug law relaxation by saying that "crime is multi-factorial." He apparently agrees that social problems can be multi-factorial, but is quick to seize on any time series trend or state-level data that is favorable to his story.
I have seen attempts to "control for confounders" by comparing legalizing states to their non-legalizing neighbors. I discussed one such study here. There are several problems with these studies, including that the neighboring states are not good controls for the legalizing states (Idaho is like Colorado, except for legalization? Really?). Also, the proportion of the population turning from non-users to users is small, ~7% of the adult population. Blaming even a small increase in accidents on cannabis posits an implausibly large effect on their driving ability. A 3% increase in accidents attributed to cannabis implies that this 7% of the population has a 43% increase in their accident frequency! That is huge. I'm a pricing actuary; I would love to know about a risk factor that's this strong, but those are quite rare. More plausibly, there's little or no population-level effect of cannabis on accidents. This study, which used a synthetic control (basically creating "synthetic Colorado and Washington" out of other parts of the United States) and comparing it to legalizing states' actual experience, found no significant difference between legalizing states and non-legalizing states. Berenson mentions statistics from the Colorado and Washington DOI, but it's not clear if he's talking about the raw numbers (which are meaningless by themselves) or a rigorous attempt to tease out causality. My impression was that Sullum gets the better of this exchange, and Berenson's claims are highly speculative.
During the Q and A with the audience, Berenson clarifies his point about why/which drugs should be considered dangerous. He states that drugs which cause psychotic violence are legitimate targets for prohibition. He claims that this consideration absolves alcohol, which doesn't cause psychosis except in late-stage alcoholism, even while admitting in the same sentence that alcohol causes violent behavior. People fear psychotic violence because it's more random than other kinds of violence. That's true enough, but Berenson validates this irrational fear by saying, "...and they should!" I think this is bizarre. If alcohol causes more violence and more socially destructive behaviors, I don't think it matters that the violence is technically not in the "psychotic" category. Anyway, it's not at all clear that alcohol-induced violence is categorically different from other kinds of pharmacologically induced violence. I'm sure the spouse or child of an abusive alcoholic doesn't feel comforted by such distinctions. Rational policy should focus on objectively quantifying and minimizing harm, not fanning the flames of an irrational panic. I understand his point: People feel (irrationally) like they can control their exposure to non-random violence. They can avoid the violence of the black market by avoiding black market activities, they can avoid certain people whom they deem to be violence-prone. But they can't avoid exposure to the random whacked-out crack head or terrorist (to name another form of random violence toward which the public is irrationally obsessed). It might be defensible for public policy to put a thumb on the scale in favor of this preference, but Berenson seems to be dramatically discounting non-psychotic violence (or perhaps dramatically over-inflating the importance of psychotic violence as compared to other kinds).
Berenson says around the 36-minute mark that cannabis is "extremely neurotoxic", which would seem to imply permanent harm. But he quickly follows up by saying it can cause "Extreme psychosis after a single use, but not permanent psychosis." I don't think he knows what neurotoxic means. (Is sleep neurotoxic, given that it causes vivid hallucinations?) To get a sense of what he's talking about, he describes someone who eats too many cannabis-infused edibles and get admitted to the ER because they think their friends are aliens. To be sure, this happens. Edibles can take hours before their effects kick in, so it's easy to take too much. Naive users will eat some, feel nothing, eat more, repeat, and by the time it kicks in they've taken way too much. But, also to be sure, the effects are temporary and (as he concedes by saying "...not permanent psychosis") no permanent damage results from these "overdoses." Psychosis seems like a hysterical term for someone who takes too many edibles and freaks out, even if it's technically/clinically accurate.
Around the 1:04 mark, Berenson claims that marijuana causes some users to become "extremely violent." Earlier, around the 39-minute mark, he attempts to blame a recent uptick in violence on cannabis legalization. This is just so contrary to almost everyone's experience with marijuana use. It tends to make people mellow and lazy, not violent and agitated. Putting together all of his comments, I think Berenson is claiming that some small fraction of people with pre-existing risk factors who take very large quantities can become violent or psychotic. But given the rarity of these risk factors, it's implausible that cannabis is responsible for a population-level increase in violence. It seems very unfair to punish everyone for cannabis use given that a very small fraction of people, using in a very irresponsible and deliberate manner, will experience a problem. Sullum at one point asks if there's really no way to distinguish between the problem users and the normal users who won't experience any problems. The later comprise the vast majority of users, so it seems unfair to impose restrictions or criminal penalties on them for the behavior of a small minority.
At several points during the discussion, incarceration is mentioned. A questioner from the audience asks about incarceration rates. Jacob Sullum points out that drug offenders actually aren't a huge proportion of the prison population. Some people who make the legalization argument exaggerate the magnitude of the problem, sometimes even claiming drug laws as the solely responsible for America's outlier incarceration rates. Sullum clearly points out that we'd have to be less punitive on violent crime to make a real dent in the incarceration rate. (Read John Pfaff's book Locked In; it's an excellent source of information on this point.) For sure we imprison a lot of people for drug laws, and if you think drug laws are unjust than even one is too many. But there's no question some people exaggerate these numbers; ending prohibition would leave the vast majority of our prisoners behind bars. Berenson says, "Yes, that's all true." And he's quick to add some numbers of his own, claiming there are only a dozen or so people in Pennsylvania prisons for marijuana offenses.
This is all fine, and it's important to set the record straight and get the numbers right. If some legalizers are exaggerating the costs of prohibition, prohibitionists should correct them. (In this case Sullum, a legalizer, is setting the record straight and rebuking some of his fellow travelers.) But it's curious that prohibitionists never seem to argue in defense of incarceration. They never say, "We don't actually incarcerate that many people for drug offenses, but we should!" Berenson himself says during the debate that the sheer number of cannabis users is so large (~40 million per year) that we're not going to arrest our way out of that problem. But if we're taking prohibition seriously as a policy, shouldn't we? Isn't it awkward to argue that we should have laws on the books that we don't actually enforce? Berenson seems to be pushing some form of decriminalization. When asked by the moderator, he clarifies that nobody should go to jail for smoking cannabis. He equivocates on harder substances; under his scheme cocaine and heroin users could face some kind of prison time. But he makes it clear that he prefers some kind of drug court for most users and criminal penalties for dealers and growers. An audience member, a mother whose son went to prison for growing marijuana, asks if her son's sentence was just. Berenson doesn't say a clear "No"; he indicates that some kind of criminal penalty is appropriate in that kind of case. Sullum points out the deep moral confusion in "decriminalization" regimes, that have strict penalties on dealers but little or no penalties for the users. He says that the people causing the actual problem are the ones who use drugs irresponsibly. Typically "aiding and abetting" carries a lower penalty than the crime itself. (I recognized this as Lysander Spooner's argument in his essay Vices Are Not Crimes.) I think that this is an extremely awkward point for prohibitionists, similar to the point about alcohol. I think they could claim that, as a practical matter, it's easier to go after a single source (a large cartel or drug gang) than a lot of smaller targets. But that's morally dubious. It reminds me of the Somali legal system as described in The Law of the Somalis. If a family member of yours murders someone, your family is obliged to turn him over to the family of the murder victim for punishment, otherwise the wronged family can kill someone else from your family in the murderer's place. One can see how this can lead to a good equilibrium, in which families discipline their own members and don't aid criminals in their midst in escaping justice. But the society has to pre-commit to actually punishing an innocent person to make this work. There is something deeply morally depraved about punishing innocent parties because it's "more practical" than punishing the actual wrongdoers. It's one of many compromises our society has made to make drug policing possible. If we tolerate this kind of thing, that leaves us all deeply compromised.
There are a few other interesting parts. Berenson at one point denies that marijuana has any medical benefits, though he quickly clarifies that CBD oil has been shown effective for certain kinds of seizures. He's all for that if it works, he says. Sullum concedes that some legalizers have exaggerated the medical benefits of marijuana, which is certainly true enough, but that he's at least slightly more impressed by the promise of cannabis. He mentions the nausea relieving effects for chemotherapy patients and (I think) wasting syndrome. Berenson is insistent that cannabis is not effective for pain control, because it has failed clinical trials. My own feeling is that marijuana is probably effective medicine for some conditions, but in ways that cannot be measured in randomized controlled trials. A common effect of a cannabis high is that every little nagging discomfort is magnified. As a friend once put it to me, "I was so sensitized, I could feel my socks." As in, we get habituated and inured to these minor physical sensations and annoyances, but smoking weed brings them back into focus. My initial response when I heard that some people used cannabis as a pain reliever was "No way!" But pain is a very subjective thing, and so is pain relief. Some people get no pain relief from opioids, while to others they are a godsend. It makes sense that marijuana would have a similar hetergeneity in its effects. In fact, it's even plausible that a majority people in a randomized controlled trial will feel their pain is exacerbated by cannabis, but that some fraction of them get relief. The study could yield a null result, even though it's effective for some and not for others, and even if the participants know whether or not its working for them. Berenson is actually hip to this kind of argument. Responding to a point about a study that found cannabis doesn't increase violent tendencies, he says (and I'm paraphrasing), "When you screen for people who don't have psychotic tendencies and give them a controlled dose of cannabis, you don't get violent behavior. That's not how cannabis causes violence." It's when you let cannabis loose in the world and those people with psychotic tendencies take large doses that you get violence, in his telling. He's appealing to the notion that people have heterogeneous responses to cannabis when it comes to the negative effects. The same principle applies to the positive effects. For something subjective like pain relief or the use of cannabis to control nightmares (to mention an anecdote I heard from someone I know), it's plausible that the drug has a large positive effect on some people, but not a consistent enough effect to pass a clinical trial. I think Berenson is too dismissive here and has too constrained a concept of "medicine."
Something that frustrates me about these debates on drug policy is that the prohibitionists never actually bother to defend prohibition. Berenson opens by expressing this exact frustration, but even he fails to mount a defense. That's not to say these people don't present evidence and give moral or logical arguments for prohibition. And I'm not saying that Berenson "fails to mount a defense" because his arguments are bad. I'm saying this: even supposing we grant all of Berenson's points, how do we add it all up? How do we know whether legalizing marijuana is a good idea or not? He claims that violent crime is up in the states that legalized first, and this is consistent with his story that excessive marijuana use in some people causes psychosis (and psychosis is an enormous risk factor for violence). Suppose the causal arrow is as he says: legalizing marijuana causes more violent crime. Okay. How much more? And how much is acceptable? How much do we weigh the enjoyment that people get from these substances? Berenson seems to acknowledge that drug users genuinely enjoy their drug habits, but it isn't clear what kind of policy/decision-weight he places on it. It's really not enough to point out that some social problems worsen after drugs are legalized (according to official public health statistics), even if one solidly establishes a causal link. To do so is only to compute some entries on the "cost" side of the ledger. We have to weigh these costs against the benefits. This is not a mere exercise in computing statistics and performing causal inference to yield an effect size. One inherently requires some kind of philosophy, a moral philosophy, to weigh costs against benefits. Drug prohibition fundamentally robs us of our bodily autonomy. It puts people in cages when they haven't violated anyone's rights (in Sullum's formulation, which I find very compelling). It reassigns ownership of our bodies to the government. One could do a cost-benefit analysis by converting man-years of incarceration to a dollar figure and comparing it to the avoided harms of drug-related social problems, also converted to dollars. Frankly I find this kind of social engineering a little bit creepy. I favor legal gay marriage, and for that matter interracial marriage, for reasons that have little to do with such a cost-benefit computation. I would do so even if a rigorous analysis went the other way. There's something to be said for freedom being a value unto itself. It's not just a general meta-rule that tends toward social optimization. (Though it is that, too. People who don't value freedom in and of itself often fail on their own terms. Policy proposals are often bad by objective measures that any reasonable person cares about. The kind of dry cost-benefit analysis I'm describing in this paragraph is still important, because we need to be able to engage intellectually with people who don't hold our values.)
I hasten to add that such a computation almost certainly favors legalization of all classes of drugs. We have very good theoretical reasons to doubt the wisdom of drug prohibition. Prohibition raises the cost of a good, because users face legal penalties and supply-side interdiction raises the price, search-costs, and harms of the substance. So users buy less of it. When demand for a product is inelastic, doubtless an accurate description of addictive drugs, then prohibition necessarily increases the total costs of drug use. There are fewer users as we increase the penalties, but the costs paid by the continuing users increase faster than the costs saved by deterring users. The paper The Economic Theory of Illegal Goods: the Case of Drugs by Gary Becker et al. is the definitive treatment of this topic. I did a write-up of it here, and here is a link to the original paper, which is quite readable. Even if you suppose that drug related externalities are very large, those "externalities" are almost invariable behaviors that are already criminalized. There are already criminal penalties, so the costs of these behaviors is already internalized. Drug users already contemplate them and build them into their decision to use. (If you are going to respond by suggesting that drug users don't respond rationally to the prospect of criminal penalties, then my follow up will be to point out that drug prohibition is a series of criminal penalties. If anyone is conceding that these don't work in general, that's a major concession to the anti-prohibition side of this argument.)
Consider also the supply side. Prohibition of a good with inelastic demand also increases revenues for dealers. Quoting from Tyler Cowen and Alex Tabarrok's economics textbook (a fuller version of the quote is excerpted here), "When the demand curve is inelastic, increasing the price increases the seller's revenue." There's no such thing as "push harder" or "let's just be smarter about this." The more you push up the price, the better funded the drug traffickers, and the better equipped they are to hire mules, invest in law enforcement evasion, bribe officials, they engage in technological innovation (such as fentanly-producing labs which, once again, makes smuggling easier). See the supply and demand curves in this article by Benjamin Powell for a good graphical description of what's happening.
Advocates of prohibition are using a very shallow application of economic theory: when you increase the price of something, you get less of it. That's true enough as it is, but presumably we care about the social costs of drug use, not drug use per se. Taking the demand-side and supply-side economics of drug prohibition together, it's almost certainly a terrible policy. One needs to make heroic assumptions to rescue it.
