Pot

12.17.12

Cool it, Reason

On the Reason blog, Mike Riggs denounces my Newsweek column against marijuana legalization. Riggs' piece is mostly an exercise in name-calling. In between the epithets and sarcasm, however, Riggs raises three fact-based objections to my article. Every one of them is in error.

1) Riggs claims I am wrong to write: "Even in the 47 states that formally ban marijuana, the drug is available everywhere and at modest cost." Riggs counters that many states allow medical marijuana. But how does that contradict what I wrote? Medical marijuana states retain a formal ban upon the drug. That ban may be loopholed, but it's still the law. Only in Washington and Colorado does state law permit possession of marijuana as a matter of legal right. I used the 47 figure because I had been referring in the previous sentence to the example of California, where the medical marijuana system has collapsed into near total farce. For perfect precision, I probably should have written "Even in the other 47 states that formally ban marijuana, etc.," but the point is the point.

2) Riggs claims I am wrong to write: "Although data are difficult to come by, it’s generally scientifically accepted that Americans smoke more marijuana per person than any other people on earth." Riggs counters "Data is not actually difficult to come by" and cites the 2012 UN World Drug Report to the effect that Australians and New Zealanders are more likely to smoke marijuana than Americans.

Riggs should have been more careful. He doesn't actually link to the report, but instead to a Time magazine story about it. That Time story notes: "Marijuana boasts somewhere between 119 million and 224 million users in the adult population of the world." Caution: if your estimate spreads over a range like that, there's your first warning that your data are unreliable.

Here's your second warning: The UN stats are based on self-reported questionnaires, not the most reliable source of information on illegal activity.

That's why the World Health Organization agrees with me, not Riggs, that in the field of illegal drugs, "good cross-national epidemiological data are limited."

However, in a careful study, 22 researchers rely on WHO household survey data to generate their own international comparisons. That study put the U.S. in first place, just as I wrote.

3) Riggs claims I am wrong to state that regular marijuana users on average "have fewer friends and occupy lower rungs on the socioeconomic ladder." Those words are an abridgment and paraphrase of this assessment by the National Institute on Drug Abuse.

Research clearly demonstrates that marijuana has the potential to cause problems in daily life or make a person's existing problems worse. In one study, heavy marijuana abusers reported that the drug impaired several important measures of life achievement, including physical and mental health, cognitive abilities, social life, and career status. Several studies associate workers' marijuana smoking with increased absences, tardiness, accidents, workers' compensation claims, and job turnover.

The study cited by the National Institute specifically states:

Heavy users [of marijuana] themselves reported significantly lower educational attainment (P < 0.001) and income (P = 0.003) than the controls, even after adjustment for a large number of potentially confounding variables. When asked to rate the subjective effects of cannabis on their cognition, memory, career, social life, physical health and mental health, large majorities of heavy users (66-90%) reported a 'negative effect'. On several measures of quality of life, heavy users also reported significantly lower levels of satisfaction than controls.

And while of course there are exceptions to even the truest generalization, it's not confidence-inspiring that all but one of Riggs' counter-examples quit smoking marijuana years and decades before they achieved their great success.

Marijuana is a subject that elicits passionate feelings. But it's troubling that a magazine named for the human faculty of reason would react to attested facts in a way so distorted by emotion.