no third solution

Blogging about liberty, anarchy, economics and politics

Reefer Madness

August 1st, 2007

A British study indicates that a marijuana cigarette is five times more harmful than a tobacco cigarette. Actually, the study says “up to five times” as harmful. OK, considering most people smoke their joints without a filter, it’s plausible. But, did you catch the sleight of hand? Smoking “a joint” is more dangerous than “a cigarette,” therefore, smoking marijuana is more dangerous than smoking tobacco. Which commits the same error as the old diamond-water paradox, in treating things as abstract concepts only, such as “diamonds” or “marijuana.” When you treat things thusly, you can draw some pretty awful conclusions – like, “an object’s value is derived from the cost of the labor required to obtain it.” But enough econ-speak, this isn’t about econ, it’s about reefer madness.

So, why are the results of this study not particularly alarming? Because, whereas there are many, many people who might smoke one joint a day, or a week, there are comparably few people who smoke one cigarette a day, or a week. And there are very, very few people who smoke 20 or 40 joints a day. So even though, pound-for-pound, marijuana may be more dangerous than tobacco in some regards, this particular study is basically junk-science because marijuana is simply not consumed in the same quantities as tobacco. The Yahoo! article cites a public health concern that came to light in another recent study:

“Smoking a joint is more harmful to the lungs than smoking a cigarette and we have just banned people from doing that in public places because of the health risks.”

Last week British researchers said using marijuana increased the risk of developing a psychotic illness such as schizophrenia.

Hilarious. Citing this study, however, neglects what is probably the most important qualifier on the marijuana-schizophrenia “conclusion”, which basically amounts to saying that, “we haven’t proven anything”:

The researchers said they couldn’t prove that marijuana use itself increases the risk of psychosis, a category of several disorders with schizophrenia being the most commonly known.

Both of these studies may have been perfectly conducted – but that doesn’t mean that the results are statistically significant or otherwise actionable. On the contrary, the evidence seems to suggest that neither article yielded even an iota of scientific merit. Combining what amount to insignificant inferences from two separate studies will not yield robust conclusions. Of course, the pesky details of scientific rigor will not stop bureaucrats from citing these studies to further their war on dangerous minorities personal freedoms “drugs.” Which, is precisely what Radley Balko predicted, less than a week ago:

…Even among heavy users, and even assuming all of this data is correct, the increased risk is negligible, and the overall risk remains extremely low. And even then, the study hasn’t proved causation, and doesn’t claim to, though that’s certainly the way it’s being interpreted, and is how it will be cited by drug warriors.

It would be comically predictable, if it weren’t so tragic.




no third solution

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