Mark Kleiman stumbles into some math

… and gets lost.
He calls his post Cheech and Chong mathematics. You decide.
It’s an attempt to debunk claims regarding the amount of tax revenue that California might reap from legalization. He then works out his own estimates of how much pot that a pot smoker would smoke in order to generate that amount of revenue, corrects his figures, corrects them again, corrects them a third time, and apparently shows that the amount of tax revenue that some people are claiming would result from legalization couldn’t occur without a significant increase in use.
Fine.
This, however, somehow leads him to a completely, and outrageously, false conclusion:

So the advocates of legalizing cannabis can argue, as they do, that legalization wouldn’t substantially increase the level of drug abuse, or they can argue that it could bring in noticeable amounts of revenue. But not both.

Nonsense. All he “proved” so far in his calculations (assuming they are correct) is that the particular amount of revenue ($1.3 billion) that some people claim could be reached (not a claim that I’ve made), couldn’t happen without a significant increase in the level of drug use.
It’s obvious, even using Mark’s figures, that you can bring in a noticeable amount of revenue without substantially increasing the level of drug abuse.
I mean, come on. This is juvenile stuff here, folks. Logic 101. It’s like the prohibitionists who say that because not every single reduction in the black market that some people have predicted is likely to occur, therefore there will be no reduction in the black market. That’s just ridiculous.
I can, and will, argue that legalizing cannabis won’t substantially increase the level of drug abuse and that it will bring in noticeable amounts of revenue.
It’s true. And, despite the paucity of directly relevant evidence (as a result of not having a proper laboratory (which California could provide)), all appropriate extant evidence supports my view.
So that’s a pretty positive thing and perhaps a good enough reason to legalize all on its own, not even counting the savings from law enforcement, prisons, courts, crime, corruption, etc., etc.
Oh, and yeah, the fact that the government in a free society has absolutely no legitimate right to wield the sledge hammer of punishment — punishing the many for the supposed sins of the few.