It's not true in Europe at least. Amsterdam (where weed is legal) has the strongest strains available on the continent. They are supposed to knock the socks off even very experienced users.
Many studies like these only focus on US data and forgets about the rest of the world so they get flawed results. The strongest alcohol you can find is from Northern Europe and Russia, where it never has been illegal. In Islamic countries, where it is illegal, black market alcohol isn't stronger than anywhere else.
The article didn't seem to mean in terms of the quality within a drug type. It looks like is more about the value density of a drug. So if Amsterdam cracked down on Marijuana, then there would be more potent cocaine, crack, meth, etc. Even the strongest marijuana pales in comparison to the 'potency' of the hard drugs.
...And of course Amsterdam is also serving much of the world (pretty much exclusively, until really recently) in terms of breeding new strains. The demand for high strength was global, even though the nexus was small, and in a legal haven.
You don't offer any citations or evidence or proof for any of your claims. How do you know what kind of alcohol is available in Islamic countries? How do you know the pot in the Netherlands is as strong as you say (given you say "they are supposed to..." without any evidence)?
Anecdata: In the Perhentian islands off the coast of Kelantan, a strictly Muslim state in otherwise generally tolerant Malaysia, the only form of alcohol available at most bars/restaurants is bottom-barrel Ukrainian vodka sold under the counter. (Although I gather a few places have finally managed to obtain actual liquor licenses since my last visit.)
> The THC levels in Dutch weed are normally higher than what you are used to. Dutch Nederweed contains about 15-18% THC, while foreign weed only contains about 7.5% THC. The THC level in hash is about 19%. So, ask for advice from the coffee shop about the type, strength and effect of the drugs. If you don’t know how strong it is, take a small puff from the joint and wait for 1-2 minutes to see the effect. Inhaling deeply is not needed for the THC to enter your lungs. The effects will last 2-4 hours.
Wrt alcohol, no I don't know that. I do have met a fair few immigrants from Islamic countries and none of them enjoyed binge drinking. Very few of them even tolerated the taste of alcohol or liked getting buzzed.
Agreed, the claimed direct correlation between strength of enforcement and strength of substance is reaching too far.
But the basic idea that there exist powerful market-forces which incentivize the production and supply of increasingly strong products when a good is prohibited seems quite logical and supported by the evidence cited in the post.
Many studies like these only focus on US data and forgets about the rest of the world so they get flawed results. The strongest alcohol you can find is from Northern Europe and Russia, where it never has been illegal. In Islamic countries, where it is illegal, black market alcohol isn't stronger than anywhere else.