Is legal marijuana more potent?

Yes, here is Keith Humphreys from Wonkblog:

Although some people believe prohibiting drugs is what makes their potency increase, the potency of marijuana under legalization has disproved that idea. Potency rises in both legal and illegal markets for the simple reason that it conveys advantages to sellers. More potent drugs have more potential to addict customers, thereby turning them into reliable profit centers.

In other legal drug markets, regulators constrain potency. Legal alcohol beverage concentrations are regulated in a variety of ways, including through different levels of tax for products of different strengths as well as constraints on labeling and place of sale. In most states, for a beverage to be marketed and sold as “beer,” its alcohol content must fall within a specified range. Similarly, if wine is distilled to the point that its alcohol content rises too high, some states require it be sold as spirits (i.e., as “brandy”) and limit its sale locations.

As states have legalized marijuana, they have put no comparable potency restrictions in place, for example capping THC content or levying higher taxes on more potent marijuana strains. Sellers are doing the economic rational thing in response: ramping up potency.

How about the Netherlands?:

The study was conducted in the Netherlands, where marijuana is legally available through “coffee shops.” The researchers examined the level of delta-9-tetrahydrocannabinol (THC), the main intoxicant in marijuana, over a 16-year period. Marijuana potency more than doubled from 8.6 percent in 2000 to 20.3 percent in 2004, which was followed by a surge in the number of people seeking treatment for marijuana-related problems. When potency declined to 15.3 percent THC, marijuana treatment admissions fell thereafter. The researchers estimated that for every 3 percent increase in THC, roughly one more person per 100,000 in the population would seek marijuana use disorder treatment for the first time.

The Dutch findings are relevant to the United States because high THC marijuana products have proliferated in the wake of legalization. The average potency of legal marijuana products sold in the state of Washington, for example, is 20 percent THC, with some products being significantly higher.

I believe that marijuana legalization has moved rather rapidly into being an overrated idea.  To be clear, it is still an idea I favor.  It seems to me wrong and immoral to put people in jail for ingesting substances into their body, or for aiding others in doing so, at least provided fraud is absent in the transaction.  That said, IQ is so often what is truly scarce in society.  And voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity.  Ideally I would like to see government discourage marijuana consumption by using the non-coercive tools at its disposal, for instance by making it harder for marijuana to have a prominent presence in the public sphere, or by discouraging more potent forms of the drug.  How about higher taxes and less public availability for more potent forms of pot, just as in many states beer and stronger forms of alcohol are not always treated equally under the law?


From what I understand (I tried but did not inhale), pot as brownies, ingested, is more potent than when smoked.

The onset is slower by the oral route. When smoking, you can throttle the dose because you can feel it pretty quickly. By the oral route, you may take too much and not be aware of it until it's too late.

A California perspective here. Before legalization, marijuana was almost always sold as something that was obviously part of a plant. Now that it is legal or quasi-legal, you can have a more complex supply chain and sell food that contains marijuana, vaporizers, and other ways to more easily consume the drug. In general, these products are more welcoming to the casual, inexperienced consumer. These segments of the market are growing much faster than the classic smoked marijuana and might soon be the most popular way marijuana is consumed. So not only will it be more potent as measured by THC concentration, other marijuana-based products are becoming widely available that will make it easier to consume more.

Thanks. And isn’t this also about getting it into the bloodstream as quickly as possible?

Hmm, I don't think so. Smoking and vaporizers both are pretty fast-acting, and edibles are generally slower-acting but longer-lasting.

I think it is about accessibility. Especially if you are new to smoking, the whole process is off-putting. First you are using an unfamiliar tool like a pipe, then setting something on fire, inhaling the smoke at the right speed, not too slow because it won't work, but not too fast or you will burn yourself or cough, then dealing with all this messy ash. It is sort of a ridiculously complicated and painful way to consume a product. Compare to the experience of eating a piece of tasty chocolate that also happens to get you high.

Just the reverse.

Another California perspective here. I stopped smoking pot for several years and then resumed when my godson was getting it from a "dispensary". The pot he can get is far more potent than what I was getting back in the old days. It is so potent it can be unpleasantly potent. I hate when I wake up in the morning and can still feel it. I never thought I would ever say that I would find a pot that is too powerful, but in the last year I have encountered several types that are unpleasantly powerful. I suspect they may be salted with synthetic drugs. I miss the days when Thai sticks were the best you could get.

Ah yes, Thai stick for $10 a piece - THOSE were the good ol' days!

If it's too loud, you're too old!

TC writes: "That said, IQ is so often what is truly scarce in society. And voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity" - is there a study that shows pot smoking lowers IQ? I am not aware of one.

BTW, to increase total factor productivity, a better fix than increasing IQ is to fix our broken patent system, which does not reward pioneer inventors adequately. Most of the best and brightest in society become gatekeepers not innovators.

Bonus trivia: reading now this excellent successor to Lewis' "Liar's Poker", a sort of less innocent Gen-X version: "Straight to Hell: True Tales of Deviance, Debauchery, and Billion-Dollar Deals" by John LeFevre, Apparently cocaine use and prostitution during working hours (including networking after hours) is not uncommon in NYC, London and HK finance centers.

Purely anecdotal. I live in the epicentre of espresso and pot: the Pacific Northwest. Low or lowered IQ correlates with pot consumption. (The espresso is incidental and is taken to merely move slightly up or down on the agitation/alertness scale.)

Legal marijuana is significantly more expensive than black market marijuana here in San Diego due to high taxes and local fees .The state looked at legalization as a revenue windfall but as a result of high prices and (burdensome) state regulation of growers more marijuana is sold through the black market. I think that defeats the purpose of making it legal. Law enforcement still gets involved. People will continue to get into trouble for buying and selling weed through illicit channels.

But, revenue lost aside, legalizing pot guts the drug cartels, which cannot be a bad thing.

Bonus trivia: many famous rich got rich from being black marketeers. Not just Joe Kennedy but arguably almost everybody who is rich, including the founder of MCI, and those people who have balls to skirt and bend the law to make profit (think Smith of FedEx, who skirted the post office regulations; and pretty much all generic drug company founders). The Napster guy almost pulled it off too, but the copyright holders were not ready to accommodate him. Sad that to get rich today means breaking existing bad laws, rather than inventing something.

Or Uber. They just kept defying the law until they had a critical mass of supporters.

Car hire services were always legal

Legalizing pot and putting pseudoephedrine under lock and key pushed the drug cartels into meth. There are no pot cartels here in Ohio. All the pot (it's not legal here) is grown and distributed by local Ohioans. I believe that's the case in most of the flyover states at least.

Warren Delano(FDR's maternal grandfather) made over $100 million trading in china. He lost it in the Panic of '57 went back to china and again made over $100 million. What did this "china trade" consist of? Well there was tea and silk, porcelain and silver but the moneymaker was opium.

Not true at all in Colorado. Legal pot is very competitively priced (~$50 per quarter ounce, good quality.)

That's a good price. If it's the same potency we get in Silicon Valley, it would probably last me at least six months. I wouldn't have a problem paying double the price for that.

Back in the old days, I'd go through that much bud in a couple of weeks. I've changed, and pot has changed. Not the same friend it used to be.

is there evidence that consumption lowers IQ? Seems like a fair assumption, but I've never seen literature on that.

Marijuana may be one of those substances that when used sparingly can lead to pleasant experiences with very few harms, yet when used excessively can decrease intelligence, work ethic, productivity, etc...

It also seems plausible that the baseline conscientiousness and intelligence level of a person may affect how likely they are to use marijuana sparingly vs excessively.

But if more potent marijuana does indeed lower intelligence, then perhaps there will be a market incentive for marijuana producers to research ways that can potentially eliminate that side effect? The connection between marijuana potency and lowering of intelligence may not be a necessary one?

I'll agree with you on work ethic and productivity. I don't believe it can affect IQ more than it can affect your height. Nobody would believe that using pot makes you shorter. Nobody should believe it lowers your IQ.

"I don’t believe it can affect IQ more than it can affect your height. Nobody would believe that using pot makes you shorter. Nobody should believe it lowers your IQ."

That seems to be a false dichotomy. Smoking tobacco damages blood vessels and can make them thicken and grow narrower. From the CDC site: "Smoking harms nearly every organ of the body and affects a person’s overall health."

Isn't the brain in a more precarious construction than the musculoskeletal system?

There's not much evidence one way or another. But from a Bayesian perspective, there's a pretty low prior weight. There's very few activities that permanently lower intelligence. Millions of people are on long-term daily regimes of SSRIs, amphetamines, MAOIs, antihistamines, racetams, processed sugar, processed fat, alcohol, modafinil, benzos, opiates, nicotine, caffeine, chronic sleep deprivation, high&low exercise, all-meat diets, vegetarian diets, vitamins of every kind and dosage, anabolic steroids, catabolic steroids, high&low oxygen, high&low parental attention, high&low educational investment and virtually anything else you can think of.

Any impact on cognitive performance disappears almost immediately after the regime is stopped. The only things that I'm aware that have been shown to cause permanent cognitive impact is huffing paint, NFL level head trauma, and possibly chronic high dosage methamphetamine abuse. Given how resilient permanent cognitive capacity is, it would be extremely unlikely that marijuana is a special exception.

There is no way they have done controlled studies on all those substances' effect on IQ. In fact, I am not even aware of any studies on any of the substances you listed. The closest thing that comes to mind is that some studies show vegetarians get memory improvements from supplementing with creatine (thing usually found in meat).

Your point is that we would notice if substances could effect IQ. But I don't think you'd really notice if your friend's IQ fell 5-10 points, and most of the people who are on substances in the long term tend to be "deactivated" adults in a stable routinized lifestyle where learning and problem solving don't really matter.

So maybe it's safe to say that it's difficult to change your IQ by a large and noticeable amount. But most people are afraid that marijuana will make them subtly stupider without their realizing it.

Virtually everything I listed has research regarding the impact on cognitive performance. The fact that nothing noticeable exists is evidence that permanent cognitive impact is virtually unheard. And this isn't hard to measure. Detecting a 3 IQ point difference at p>0.95 only requires 100 participants. Not saying every possibility has been exhaustively mined. But in general if long-term cognitive impairment was common, it should literally be showing up everywhere.

Heck, even temporary cognitive impact is hard to obtain. Decades of research on nootropics and intelligence enhancement has found that even extreme regimes have only at most very moderate effects. Much less than one standard deviation (15 IQ points). Being **drunk** only lowers cognitive performance by about 10 IQ points (0.65 standard deviations).

Is it possible that chronic marijuana usage has a very subtle effect? (Not talking about actually being high, just sober periods of a heavy active user.) Maybe. But that's a very qualified maybe. The effect would almost certainly be no more than 2 IQ points. And unless the dose-response was very nonlinear for some esoteric reason, virtually no one but the very heaviest of users (a quarter ounce a week or more), would be impacted. Anyone who's concerned about their joint a day habit, would almost certainly get more mileage out of putting that effort to consistently getting a full night's sleep.

There are studies showing negative effects of continued marijuana use, especially on the adolescent brain

The Drug Czar's office is not exactly a reputable or unbiased source. However even given that, it does not support your claim:

> However, recent results from two prospective longitudinal twin studies did not support a causal relationship between marijuana use and IQ loss. Those who used marijuana did show a significant decline in verbal ability (equivalent to 4 IQ points) and in general knowledge between the preteen years (ages 9 to 12, before use) and late adolescence/early adulthood (ages 17 to 20). However, at the start of the study, those who would use in the future already had lower scores on these measures than those who would not use in the future, and no predictable difference was found between twins when one used marijuana and one did not. This suggests that observed IQ declines, at least across adolescence, may be caused by shared familial factors (e.g., genetics, family environment), not by marijuana use itself.45

@Doug. I would not be so categorical. The article notes that the counter study examined a shorter duration and did not consider dosage. I think it still is an open question.

"Detecting a 3 IQ point difference at p>0.95 only requires 100 participants."

Okay. Where are the studies that test IQ before and after long term use of these substances?

And my whole point behind detecting small differences wasn't that they couldn't be studied. I believe they can be fairly easily, as you outline. My point was that if you didn't study them, you wouldn't notice small IQ drops just walking around in your daily life. As far as I know there's no study on long term changes in IQ vs marijuana consumption.

Marijuana legalization: somewhat overrated
Psychedelics legalization: quite underrated


No psychedelic is addictive as an advantage. They aren't always pleasant either.

That's for sure. The more you use the less you want to use, in my experience. One of these days, I'd like to have my third trip on shrooms, but I'm not is a rush to do it. Sometime in the next 10 years, maybe.


I'd also make a similar claim for MDMA legalization.

"if wine is distilled to the point that its alcohol content rises too high, some states require it be sold as spirits (i.e., as “brandy”) and limit its sale locations."

Wine isn't distilled. The alcohol by volume comes from fermentation alone. Spirits are distilled. The process of production is distinct in these cases. Brandy isn't a kind of wine. It's a spirit produced by distilling wine.

This is a pedantic point, but maybe relevant because many governments differentiate alcoholic beverages according to their production methods. It's interesting to think about how distinctions along production method lines might work with marijuana as well. It seems like the products in dispensaries are differentiated in terms of packaging, but not in terms of the production. It would be difficult to justify a distinct tax categories for higher THC or CBD products, then. It would be easier to justify only graded taxation based on these chemical contents.

I think Tyler's referencing fortified wines, like vermouth, port or sherry.

I see. That might be right. All the same, fortified wines are made by blending spirit with wine. Hence, fortified wine is a distinct category.

Eh, there are sometimes sharp steps in taxation or treatment of alcoholic that don't make distinctions among production methods, so I don't see your point. Plenty of states, at various times, have prohibited beer with alcohol levels above a certain point, even while spirits with much higher levels were available. Part of the argument was in possible customer confusion, but I don't think that it would be difficult to justify a sudden change in category, even if I might prefer a graded taxation based on THC level.

The beer example is a good one. Thanks.

The alcohol content of wine can be boosted by reverse osmosis filtration to remove the water. This also increases the flavor, and is widely practiced.


Got a link? Anything??

Good post from Cowen, and some good comments. Agree with most.

'Although some people believe prohibiting drugs is what makes their potency increase'

So, how is the hashish market doing in the U.S.? Or the opium market compared to the heroin one?

Smuggling has its own framework, and it now appears that the potency of marijuana is reaching the level that hashish always possessed. Hashish being the main way that Europeans consume THC, at least according to wikipedia.

'And voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity.'

Easy for a teetotaller to say, unless there is any evidence that saying 'hold my beer' is a sign of enhanced intelligence -

The last time I saw hash was before I used up my last roll of fax paper.

Not working from a large sample size but all the dispensaries I've been to sell hash.

More potent marijuana is a public health benefit. By far the most deleterious aspect of marijuana is the fact that it is smoked. Like cigarettes, or any other type of smoldering organic material, smoking carries a dizzying array of health issues. Those issues are linearly related to the total weight of dried material. The psychoactive chemicals in the plants (nicotine, THC, etc.) have minimal health consequences.

Therefore the most important consideration is to minimize the quantity of burned material per unit of psychoactive compound. I.e. to smoke the highest potency plant material possible. A marijuana user smoking a 30% THC strain (common for legal states in 2018) only needs to subject his lungs to 1/10 the punishment as someone smoking 3% ditch weed. This is counterintuitive because we're used to thinking about alcohol, which is diluted with harmless water. But imagine if all drinks were watered down with lead-contaminated tap-water. Then it would a public health imperative to get people to switch from beer to high-proof rum.

One word: Bhang

What is the basis for your assumption that amount of psychoactive substance consumed will stay constant, so that the amount of marijuana consumed will decrease as the potency increases?

This does not seem like a good assumption. Higher potency makes it easier and cheaper to consume more psychoactive substance, probably makes it more enjoyable to consume marijauna, and also likely increases addictive effects that will have a compounding effect of increasing consumption. The post actually points to evidence suggesting the latter.

I think you misunderstand the core of my argument. To a first order approximation 100% of the public health issues with marijuana come from people smoking a dried plant. Even with the worst plausible estimates regarding THC's health impact, it's a rounding error next to smoking. This evidence for this is incontrovertible.

Let's say ditch weed with potency of 5% is replaced with high-grade hydro chronic with potency 20%. In response to this high quality marijuana, consumers *double* their THC consumption. That would still mean that the total volume of weed consumption falls. Take someone who used to smoke an ounce of ditch weed a month, that's 2.8 grams of THC. Even if he ups his THC consumption to 5.6 grams per month, his monthly weed consumption would by 50% to half an ounce. That's a huge public health win, because he's dramatically reduced how much smoldering organic compounds are entering his lungs.

The only way your objection holds water, is if THC consumption is super-elastic to marijuana THC concentration. I.e. if THC concentration rises by 1%, then THC consumption rises by over 2%. That's clearly absurd. Given that high-end legal cannabais potency is at least five times higher than average strains from 1995, your model would imply that the rise in weed quality would account for a **2500%** increase in marijuana consumption. That clearly is absurd, we aren't smoking two dozen times as much weed as two decades ago.

I'm not sure where you are getting the "2500% increase" from out of my comment. I didn't specify any specific relationship, only provided some reasons why we might not expect weed consumption to decrease in response to potency increasing.

It's not obvious to me that the 500% increase in potency since 1995 must have been associated with a decrease in the total amount smoked (either in aggregate or per user).

Also, why are all of these people visiting addiction centers, if there is no public health issue?

Here's the claim you're making. Let's say we replace beer with vodka. Will that cause people to drink more moles of alcohol? Probably. Will that cause people to drink more total fluid of alcohol beverages? Almost certainly not. It's like saying someone who normally drinks two pints of beers in a sitting is going to drink 32 shots once he's offered vodka. Just because they're the same total volume.

Is smoking marijuana that big a public health issue, though? I thought it was way less harmful than smoking tobacco.

Yes. Because the total volume burned by a marijuana smoker is significantly less than a tobacco smoker. One cigarette contains approximately 1.0 grams of dried plant material. A pack of day smoker inhales the smoldering byproducts of 140 grams per week. In contrast a very heavy marijuana user may go through a half an ounce (14 g) of high quality weed a week. The marijuana smoker is consuming 90%+ less smoke than the tobacco smoker. That's why the total public health impact is relatively low.

But a very large share of credit has to go out to America's talented and dedicated marijuana cultivators. In the 1970s it wasn't unusual for common strains to only have 1-2% THC concentration. Modern high-end strains like Ghost Train Haze regularly exceed 25%. Hence 1970s users would have to smoke far more volume to achieve the same high, which takes a higher toll on the lungs. The 1983 Reggae song "Smoke Two Joints" describes that quantity of weed as a typical dose for a single person to achieve a mild high. (Not to mention 1970s joints were far larger.) Nowadays, high quality legal weed doesn't require more than two *puffs* before the user becomes sufficiently intoxicated. If not for the innovation of the West Coast's marijuana industry, current cannabis consumption levels would carry significantly more public health issues.

Agreed. I've had Ghost Train, and it's one of those powerful weeds that can be unpleasant. Two tokes? I don't think so. One very small toke is plenty. More than that risks how long you'll sleep or what you'll feel like the next morning.

You don't get it.

Marijuana smoke doesn't contain tar, like tobacco, and doesn't represent the carcinogenic risk of the latter.

Doesn't contain tar? What do you think that brown stuff is which accumulates in the bong?

That and people often put tobacco in their joints to add bulk.

Personally as a decadent millennial urban elite I see very few people actually smoking weed these days - most use portable loose leaf vaporizers (eg Pax), vape pens with concentrate, or edibles.

I agree with Tyler on some regulation but disagree on why this regulation should be implemented.

In the case of alcohol, regulation is great because I can safely buy spirits without worrying about going blind or dying because of methanol. For tobbaco nicotine doesn't kill, the rest of the cigarette does the job. The quoted study says THC went on average from 8 to 20%. That means there's 80% of something else being smoked.

This phrase is key "Use of cannabis products with high concentrations of THC has been linked to poorer mental health and addiction outcomes". First, it's a link, not a causal relationship. Then, the quoted articles don't support this idea. An article says "smokers are in higher risk of psychosis", not "20% THC pot has higher risk of psychosis compared to 8% pot".

Considering the practical realities of alcohol and tobacco, I'll try to study first the adverse health effects of ALL the components of marijuana and then focus on THC. Then regulate to insure quality control.

How about higher taxes

The solution to all perceived problems, from drug and alcohol abuse to excessive energy consumption to every supposed externality.

And the people who try to evade the higher taxes on marijuana will be killed, a la Eric Garner? Taxes don't collect themselves. I don't see the huge improvement in social justice under that system.

Revisit this topic when you can buy it just as easily as a pack of cigarettes or a 6-pack of Bud Light,

I don't know, Tyler, reading that "non-mood affiliated" climate change thread made me want some potent cannabis. Hedonism strikes me as the only sane response to a world so full of powerful people determined not to know or not to care what they are doing.

Hey, hedonism worked for the Romans. Well, for several centuries.

Marijuana, like its more popular toxic cousins alcohol and tobacco, are extremely profitable because the largest costs of their use are born by neither the seller nor the typical buyer. Estimates vary but the numbers are highly suggestive that something between 1 and 5% of marijuana consumers will develop psychosis; there is an established dose dependent relationship between marijuana use and psychotic symptoms. Lifetime cost of treating psychotic patients are typically in the low millions per person.

I fully suspect that this legalization will end just like alcohol did: a bunch of companies will make massive bank off giving the public what it wants, society will be impoverished by a decent bit twenty or more years later when the medical bills come due, and taxes will never raise to a level that offsets costs unless we count it as a win to have users die young. Organized crime will get more violent and still be with us, as it continues to be in Portugal. Taxation levels that actually pay off the social externalities will undoubtedly spawn a new round of lawbreakers; lawbreakers the public will have no stomach to fight or punish hard enough to deter.

So we likely end up with an equilibrium like we see with alcohol and cigarettes: a small subset of people will die, a larger subset will become massive drains on social resources, and the wealthy libertines will either shun those who use or (more likely) insist that because they can manage moderation and see no harm why should they pay to help those who cannot control themselves?

Between 1 and 5 percent of all people will develop psychosis. Schizophrenia is the first or second most common major psychiatric disorder, depending on how broadly you define depression.

Tyler has it all wrong. More potent = better. Less potent = worse. Its not all that addictive, more of a habit. Don't smoke anymore because I support a family and was paranoid about one police stop ruining my family.

But, the years I smoked were the best years of my life. The thought of legalization where I live brings tears of joy to my eyes. See, I have a depressive disorder called dysthymia, persistent anxiety, and Crohns. Pot was the only thing that made me relax and enjoy life. And yes, I got an advanced degree in STEM and held a six figure job back before I had a family to support. I could sleep nightly without waking up at 2am in a mild panic, didn't have nearly as bad digestive issues, and generally I liked life better.

Since I quit, I kindof manage. I drink more. Alcohol is actually addictive. If you quit a heavy pot habit you will have 1-2 restless nights and by day 3 you completely forget about what its like. WIth a heavy drinking habit you will have to take a few days if not a week off of work to quit. Not to mention the damage that alcohol does to your mind and body.

I realized by about age 25 that I can't be "high on life." I need a chemical crutch to be normal. The legal drug industry wants to give me massive doses of anti depressants that stop working after a few months at most, or Xanax which, geez that stuff is dangerous.

I take a different tack. For a segment of the population, pot use should be encouraged. It shouldn't be in edibles or extracts - high quality plant stuff is fine.

As for the IQ stuff, thats debatable. But for some of us, we would gleefully trade a few IQ points for being happy.

There is a direct dose response relationship between THC and risk of schizophrenia. We have followed it through multiple longitudinal studies. The data is at least as solid as that for smoking and cancer in the 70s.

~90% of patients using THC will be safe. ~10% will suffer negative consequences; they will be disproportionately minorities and poor. A small fraction will develop psychosis and for some of those it appears to be permanent.

This all bog standard research. In fact we are required, by law, to place warnings about side effects on Marinol (i.e. pharmaceutical grade THC) that include:

Psychiatric disorders: Delirium, insomnia, panic attack

Nervous system disorders: Seizures, disorientation, movement disorder, loss of consciousness

So please just stop. We have high potency THC. It comes in a bottle with precise dosing. It has known side effects that are pretty nasty. And that is without smoking it with a bunch of carcinogens. When you have treated your 100th patient who did have bad side effects from marijuana, then you can get back to me with tales of how harmless this stuff actually is.

Safer than cigarettes or alcohol is a bar so idiotic we should never even begin discussing it.

Marijuana is, by your description, pretty much a direct analog of alcohol. 90% of users do so responsibly and are fine, 10% have negative consequences. I won't get into a which one is worse debate, but there's no question weed and alcohol are similar in this regard. Either ban both (totally unworkable) or legalize, regulate, tax both (what we are seeing now).

It depends on your goals and your willingness to put in effort if prohibition works.

Alcohol bans worked quite well with a large drop in the actual quantity of alcohol consumed. This was true in the US, Finland, Denmark, and plenty of other places. We saw much less liver disease and drops in petty crime (likely offsetting all the crime of the mafioso). Judging by the health effects, prohibition was vastly more successful than just about any other public health policy.

Likewise, in economic terms, there is not a huge amount of difference between fines and taxes. Like China's One Child Policy toward the end, we could very easily tamp down demand by keeping marijuana "illegal", but not incur the incarceration costs from current policy.

I suspect the best policy is something like Sweden's take on prostitution where selling sex is legal, but buying it is not. Decriminalize certain aspects (e.g. small scale possession and home use) while retaining, but seldom enforcing, illegality on other aspects (e.g. cultivation, production, sale, and large scale possession).

I have seen no evidence that legalization has actually helped mortality, crime, or other statistics in Colorado. I suspect all those harms to be reduced quickly if this will actually reduce crime. I suspect we will not see the full effects from the psychiatric side effects for 20-30 years.

You can make an excellent case on grounds of freedom or natural rights to legalize recreational drugs by advancing human freedom, in turns of harm reduction, legalization is basically a wash with both sides able to p-hack their favored outcomes.

Which is why I expect marijuana legalization to proceed just like alcohol. There will be a brief period where everyone will enjoy and few of the negative effects are counted. The criminal rackets will redeploy their skills to new territory (e.g. human trafficking). Those who cannot self-moderate will destroy their lives. The rest of will pay for that (e.g. incarceration, Medicaid, etc.). Some of those who cannot or will not moderate will suffer serious consequences (like liver failure or psychosis); and some of those will spill over onto innocents (e.g. drunk driving, psychotic violence). This will be mostly confined to poor areas where policy makers tend not to liver or interact so it will just be another problem blighting the lower classes so the upper classes can enjoy themselves more easily.

TC and his worship of IQ, as usual. I maintain IQ does not adequately measure intelligence. If I understand TC's point, we each should have the right to do anything we want to our own bodies. This would seem to imply that TC believes the rest of us should pay for adverse outcomes of ANY self-destructive behavior. Or perhaps he doesn't believe in cradle to grave cost accounting.

Cowen needs to keep in mind that regardless of pot potency consumers till smoke or eat until they get to a comfortable high. That comfortable high hasn't changed but the amount of material needed to get there been drastically reduced.

ER admissions for cannabinoid toxicity doubled following legalization in Colorado. Likewise we are seeing increases in cannabinoid hyperemesis.

It would be shocking if this did not happen. Users are terrible at dosing correctly, after all every bloody die I work these days I have at least one person coming in because they dosed too high on heroine. Marijuana has a much wider margin before you die, but I see a demonstrated inability to dose THC ingestibles quite commonly. Likewise a users want a comfortable, but affordable high. Legalization lowers the cost of getting higher as you can have more obvious high symptoms for longer without worrying about getting arrested (as much). Without massive taxation (encouraging black market sales), the straight price reduction makes things more affordable.

Most heavy marijuana users have difficulty affording their preferred high (it takes a LOT of old school pot to get that high); lowering the price constraints and allowing for modern consumable engineering makes it much easier for the tiny minority of users who consume the vast majority of marijuana to afford strong highs.

In the real world, we have seen increased cannabinoid toxicity and by all appearances reduced price has lead to increased consumption on a per capita basis. All in line with expectations.

Tell me about these cannabis fatalities?

Additionally increased and more widespread use does not mean that the potency of marijuana is a main effect on ER admissions.

Cannabis fatalities rank just ahead of overdoses of homeopathic medicines. Both are a national shame.

> Marijuana has a much wider margin before you die

The lowest LD50 rate I could find for an oral dose was 482 mg/kg in mice ( Even if the real LD50 for humans is 1/10 of that, a 150lb person would need to consume over 3.2g of THC. That's an insane amount. For context, those potent little gummies usually contain about .05g each.

Also, you're acting as if extracts and edibles did not exist prior to legalization which is not the case at all. If anything legalization can increase transparency about dosage. Those brownies your friend made back in highschool might have been 20mg/piece or 200mg/piece, it was hard to know without trying them out. Now you can see on the package what the dosage per serving is. I think a lot of people just don't know what a reasonable dose is or don't give THC enough respect and end up panicking when they take too much and it feels more like a psychedelic experience.

Oh please. Marijuana has a low risk of acute mortality, it has a high risk of significant sequella. Most people will not die from hyperemesis; on the other hand they will come to see people like me. That is expensive, if you come in massive amounts of vomiting I need to do a bunch of tests to rule out dangerous stuff. This costs a lot of money. This becomes more common with legalization.

Likewise, with neurotoxins you can have extremely low LD-50s, this doesn't help if you end up developing lifelong neurological symptoms.

All I know is that ER visits for cannabinoid codes spiked with legalization. Incidence rates for unpleasant and costly related medical issues spiked. The evidence is pretty clear, legalization means we will have a spike in related issues. Maybe this is not as bad as the harms of prohibition, but this happens every single time.

For instance, alcohol prohibition saw a dramatic decrease in cirrhosis and when we legalized alcohol we had a dramatic uptick in the amount of money spent on treating liver disease. The harms were and are extremely disproportionately borne by the poor and minorities. Organized crime became more violent and harder to police.

But do tell me how the patients I see don't exist.

"Organized crime became more violent and harder to police."

After prohibition was listed? Thats false. You can argue that prohibition provided some health benefits, but there is no way it decreased organized crime.

After prohibition, the Mafia did not wither up and die. Instead it shifted focus into prostitution, extortion, and loan sharking. All of these activities increased the lethality and violence of the mob. This is why organized crime is vastly larger (and more violent) than it ever was in the 20s. Running booze is an easy way for criminally inclined individuals to make bank. Take that away and they will either find something else to sell that is more toxic/addicting or just use their violence elsewhere. Crime is inheritably substitutable,

In all the rest of economics we believe that human skills are capital that will be utilized in something approaching cost effective manner and be reallocated as needed after market shocks; why the criminal skill sets would be different is beyond me.

"After prohibition, the Mafia did not wither up and die"

Maybe but they grew to the problematic proportions that they did because of prohibition. And by the way, id love to see the proof that the lethality and violence of the mob increased after prohibition or that organized crime is vastly larger (and more violent) than it ever was in the 20s. My guess is that the only way that is correct is in the context of a different prohibition, IE the drug war, which hardly proves your point.

To be fair, your first post talked about mortality, not adverse non-life threatening reactions.

I looked up hyperemsis because I'd never heard of it. This sounds like an unpleasant reaction to over-consuming cannabis that some people get. It also looks like it's treated by stopping cannabis use. In other words it's a side effect that some people can get so they should stop using the drug.

>All I know is that ER visits for cannabinoid codes spiked with legalization. Incidence rates for unpleasant and costly related medical issues spiked. The evidence is pretty clear, legalization means we will have a spike in related issues. Maybe this is not as bad as the harms of prohibition, but this happens every single time.

This sounds reasonable. Do you know if this levels out over time or if the rates remain elevated? I would expect a significant spike as new users take the now legal drugs, probably without due caution. I would then expect the rates to return to normal or maybe a bit of an elevated level since there's less stigma around the drug so going to the hospital is a legit thing to do even if the symptoms don't seem like an emergency, as well as the first-timers who tried the drug initially after legalization and then stopped because of their bad reactions.

>But do tell me how the patients I see don’t exist.

I didn't say they didn't exist, I said they're not dead. I didn't even argue that the numbers wouldn't increase. Don't be so combative.


I never discussed mortality. I said "toxicity" which includes both lethal and sub-lethal harms. Last I read in the trade publications, there was a huge spike post-legalization with reversion to a new higher baseline for cannabinoid codes.

Hyperemisis is pretty much a giant nothing in terms of long term patient harm. Patients who get it really should discontinue marijuana as they are likely at increased risk for esophageal cancer, GERD, tooth decay, and a few other nasty things. On the other hand, if a teenager gets hyperemetic at home, mom is going to bring him in. Once here, I face malpractice if I do nothing to ensure that this isn't something bad (e.g. bowel obstruction). So I will under tests. If I am having a good day that is just a marijuana screen, blood panel, and an ultrasound - call it $1000 and forget it. If I am having a bad day, we will need to bust out a CT and some antibody tests. All of this is taking up time and all this means that someone else, who say came in with a painful, but not dangerous, broken bone gets to wait awhile longer. Basically it burns money, but not much health.

What is useful about it, is that we see it inordinately commonly in people who cannot self-dose. Thankfully, THC either whacks out your brain or gives you a bunch of stuff that will pass unlike heroine where you just end up dead. So we can say with some pretty good certainty, that no legalization was not just a bunch of people buying the weed they would buy anyways. We have some pretty good evidence that we did see a bunch of people unable to dose to something they could handle. Increased hyperemesis basically means we have more users or users are hitting more.

Given the current medical evidence, we know that basically either one of those means were are creating more schizophrenics. Schizophrenics tend to cost society millions of dollars. Again, you can argue that these costs are lower than current policy or make the facile point that alcohol/tobacco are worse ... just not that we will not some increases in some costs.

Marijuana legalization seems unlikely to actually reduce harm all that much and has some nasty timebombs built in. Maybe we should all just "live free or die", but let's be honest about where things stand.

The Mafia grew to problematic proportions in Sicily when it became an extortion racket on the lemon trade. The Yakuza got problematic over similarly distant sources of income.

Booze was a giant bonanza of cash, but like all cash bonanza's; competition brings down the profits. This will work the same way. Legalizing pot in Colorado has not made any dent I have seen statistics on for: petty crime, incarceration, murder, or all-cause mortality. Criminals will move into other ventures, like they always have.

Not to nitpick but
> Users are terrible at dosing correctly, after all every bloody die I work these days I have at least one person coming in because they dosed too high on heroine. [b]Marijuana has a much wider margin before you die[/b], but I see a demonstrated inability to dose THC ingestibles quite commonly.
sounds like you were implying that people overdose and die from THC.

Regardless, I think you bring up some good points and I wish people were more open to talking about the negative effects of legalization. I'm firmly in pro-legalization camp but I don't think it helps anybody if we pretend that it's all upside and there are no costs.


Sure typed too fast so it is not grammatical, but I feel the most reasonable reading is that

heroin uses regularly come in and die after taking too high a dose of heroin, and now cannabis users come in sick but don't die because 10 times the normal dosage might be lethal for heroin but not for cannabis has a much wider margin of error so they didn't die from taking 10 times the normal dosage.


The point of that mangled paragraph was that I routinely see people who die from overdosing. The fact that this is a likely outcome from heroine use appears to do very little for their dosing skills. So prima facie we should not expect drug users to be able to adequately dose with different potencies than they expect. For what is worth, I also have seen a lot of lethal ODs from cocaine, alcohol, and even nicotine replacement patches.

Cannabis does not kill when you OD. It does, however, show up in my ER and has been doing so with increasing frequency ever since "medical marijuana" passed. Given that drug users are literally coming in with toxic symptoms that go away if they would just take a break from the pot long enough to wash it out of their system ... I can pretty safely say that, no, marijuana users are not demonstrating particularly good habits at dosing.

Given that I do see marijuana ODs, I can say with pretty high confidence that we will be seeing more psychosis in the future. If users cannot even manage to avoid using amounts that cause severe vomiting in a short time frame, exactly how good are they going to be at dosing around long term neurodegeneration. Given how terrible patents are at dosing around similar agents, again I suspect there will be some rather large medical bills to pay. The people whose lives will be ruined through their unwillingness or inability to moderate will not be reading this blog, ever, but even if we care not at all what people bring upon themselves, we will be paying for a lot of treatment, incarceration, welfare, etc. for people who do use irresponsibly.

Every silly Just So Story about how pot is special needs to square with what I see brought in through the big bay doors. There are very real costs to legalization. I am not convinced that it is better than some form of decriminalization, but I become less convinced of legalizations merits every single time I read one of these debates. It also makes me wonder if pot might have some odd neuron preference for critical reasoning skills.


From 1 to 2? Do you have any numbers? The rest of your post of unsubstantiated assertions bla bla bla blah

Yeah I'd love to see the amount of cannabis overdose patients compared to the number of alcohol overdose patients. My guess is alcohol wins by a 30:1 ratio or possibly higher.

Also if I had to choose between the average dumb college freshman downing a fifth of vodka in one sitting or eating an entire bar of cannabis chocolate, I'd take the chocolate every time.

voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity

Cheap Chalupas.

This post is one of the worst I've read here at MR.

1. Illegality drives potency and purity because it lowers transport and concealment costs. THC increases aren't being driven by transport or concealment costs, but by a simple drive to increase yield. When corn yields per hectare increase, does anyone write blog posts about how counterintuitive it is that *legal* corn keeps getting more "potent" per hecare?

2. There is no evidence that I'm aware of that links moderate THC use to reductions in IQ. Yet here it is glibly implied that of course there is such a linkage. Where is the evidence?

3. "Potency rises in both legal and illegal markets for the simple reason that it conveys advantages to sellers." To sellers? Only? What does that even mean? Are "sellers" growers? Distributors? Or just street dealers? It's not exactly an economic claim.

4. "More potent drugs have more potential to addict customers, thereby turning them into reliable profit centers." This is increasingly sounding like a regurgitated script from a 1987 DARE video. THC is not addictive.

5. "And voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity." That is a great point, and is why I don't think anyone should read the linked piece.

6. "Ideally I would like to see government discourage marijuana consumption by using the non-coercive tools at its disposal." I would like to hear more about the "non-coercive tools" that goverment has. What are some examples, whether THC-related or not?

7. Now, sadly, comes the fact is that I'm sympathetic to the main thesis here. High THC content may be a reason to regulate some plants differently than others. I just wish proponents of this view could advocate for it without littering their writing with all the other incorrect garbage.

Remember, readers, that Attorney General Sessions

Will notice all those commenters who respond to the question

Of whether legal pot is more potent

By referring to the the results

Of their own taste tests.

Be warned.

I don't understand this libertarian squeamishness against banning items.

Sure, banning something doesn't eradicate its consumption in society. But if you strongly believe something is wrong, you ban it.

Laws against bigamy have worked in changing the culture on the ground. Laws against marijuana and alcohol can work too. If there is a will to enforce them with an iron hand. And let them be in force for a few decades. The culture can be engineered for the better.

We have managed to eradicate human sacrifice. We can do it with drugs.


Global warming has a strong inverse relationship with human sacrifice. The gods may be telling us something.

iron hand

round up the users and machine-gun them.

That should work!

Have we eradicated human sacrifice? The Spanish decisively put an end to state-sponsored human sacrifice in Mexico, and in general, the practice has been out of fashion among European cultures for many centuries (with the arguable 20th-century exceptions of, e.g. several million Jews and kulaks here and there, depending on one's definition). However, I've seen a few recent short films from Iraq and elsewhere suggesting that not all of the world's gods have lost their appetite for human blood.

If we're going to make a libertarian-friendly case for draconian bans on harmful substances, refined sugar should be the first to go (or at least a close second after tobacco), as US taxpayers will be increasingly required, under increasingly bipartisan consensus, to pay the medical bills of their increasingly obese countrymen. Once that budget-buster is under control, any remaining resources and political will can be used to round up, imprison, and if necessary execute the brewers, growers, stoners and drunks of America, so civilized people can better enjoy long, healthy, monogamous lives.

Quick question: How many killings of consenting adults for victimless crimes such as: marijuana use, acohol use, or prostitution are you willing to tolerate to violently force them to conform to your lifestyle choices? Also who decides what should be banned and what shouldn't? Keep in mind that due to the increasing urbanization of American, and resulting spread in liberal ideology it's unlikely that someone with your values will be making those decisions.

The problem is not with bans or their supposed futility. The problem is with the lack of belief in the establishment in its own notions of right and wrong.

Would Tyler give his daughter marijuana or cocaine at dinner? Am sure not. If a substance isn't good for your daughter, how is it good for he society at large?

Who are you to decide what's good for society at large? Shouldn't we allow adults to make their own decisions regarding how to live their lives? They are the ones who know themselves the best, and have to deal with the consequences of those decisions. I wouldn't want my son to be an IED disposal technician due to the danger. But I don't think that society is better off without IED disposal techs.

"Potency rises in both legal and illegal markets for the simple reason that it conveys advantages to sellers. More potent drugs have more potential to addict customers, thereby turning them into reliable profit centers."

In a competitive market, should not be a collective action problem there? After all, even if a seller can make a consumer an addict, the consumer can satisfy his addiction buying also to other sellers, meaning that each individual seller will have low interest in "addicting" his buyers.

With legalization, sellers can also make uniform dosages available, something impossible when it is illegal. A smart person can avoid taking too much. By using known strains and measured quantities, buyers can ensure they do not use too much. Also, various strains seem to have different sensory effects. A simple form of regulation would be to follow alcohol type regulation, which discloses the amount of active ingredient. Edibles from some sellers do inform the buyer how much typically one should consume.

Higher potency also means one can get high with less smoke going into your lung. The evidence with light cigarettes is instructive. People smoked more cigarettes to get the same level of nicotine, damaging their lungs even more.

Government involvement has unintended, adverse consequences. Cato just examined the blundering way the government is going about the opioid matter. People may turn to other sources if legal marijuana becomes expensive or difficult to get. Black markets easily develop even alongside legal markets.

Pot may lower IQ (but there is evidence it facilitates some forms of thinking). But one has to look at the alternative. There is a reason people want to alter their feelings and perceptions. Sometimes it is pain relief (including psychological pain). Much better to do it with a drug with the fewest side effects. Alcohol kills and reduces life expectancy though internal effects (harming organs) and external ones (auto crashes, promoting psychotic behavior -- the raging drunk, etc.) I predict that in ten years we'll see positive effects on life expectancy with marijuana use as there will be a drop in heroin addiction, drunk driving crashes, and a lowering of stress related illnesses. Already there is preliminary evidence of that as to hard drug use.

Rich, smart people will use pot safely. Poor, dumb people will get dumber and poorer, but they are already getting dumber and poorer from using other substances we have made/kept legal. May as well just F'em.

Got it.

Government: "You can get high......but not too high."

Is the IQ claim from this study?:

"Grade improvements are driven by younger students and the effects are stronger for women and low performers. In line with how cannabis consumption affects cognitive functioning, we find that performance gains are larger for courses that require more numerical/mathematical skills."

As a high school math teacher in a low income area I'll cosign this. Math and science are total systems that build on prior knowledge and they are hard to teach to students who can't remember anything from one day to the next.

Also I see a lot of people talking about IQ and how improving IQ is a better solution than banning marijuana. They are totally missing the point.

It's not a question of IQ AT ALL. Some of the most notorious sex offenders are often great achievers in society with high IQ. The fact is human nature is flawed. And even incredibly intelligent people have a weakness to give in to the temptations of the flesh (this includes women, drugs, among other things). The sensual life has its appeal over the intellectual life. And this is just as true for high IQ people as low IQ people.

A better guard against this is religion and austerity. And not improving IQ.

We can't all be monks. It would be the end of the human race.

Not asking for that at all. My point was - Drug abuse is not about IQ per se. Many high IQ people can fall a prey to addictions.

Abstinence is a virtue that stems from religion to a great extent. Not from high IQ.

"Abstinence is a virtue that stems from religion to a great extent. Not from high IQ."

LMAO! Read about all of the pedophilia scandals reverberating though: the Catholic church, Mormonism, and Islam. Then tell me again how virtue is connected to religiosity.

wouldn't increase in taxes engender another illicit marijuana market just as it is for illicit cigarettes ?

And voluntary consumption decisions that lower IQ are not something we should be regarding with equanimity. Ideally I would like to see government discourage marijuana consumption by using the non-coercive tools at its disposal, for instance by making it harder for marijuana to have a prominent presence in the public sphere, or by discouraging more potent forms of the drug

How about no?

The last thing we need is the State deciding it's in charge of our lives "for the good of our IQs" any more than any other reason.

Stop it.

Just. Stop.

(Note, none of the "discouraging" or "making it harder" you suggest is non-coercive, is it?

I mean, "making it harder to have a prominent presence" means ... prohibitions, or limits, or fees, or some other coercive mechanism of enforcement, no?

Not just asking them nicely to please not advertise and then being pouty-faced and doing nothing else when completely ignored, yes?

It's just not as coercive and as directly coercive of consumers as prohibition.)

As opposed to what?

Writing speeding tickets? Paying taxes? Enforcing criminal justice?

Everything the state does is ultimately coercive. Perhaps you subscribe to some anarchist doctrine that has never worked in the history of the world.

The desires of some of the populace are always going to be frustrated by state coercion or somebody will gather up some guns and found a new state. Just because you like pot, does not mean that you need throw out all manner of coherent argumentation.

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