The war over weed: if you know why marijuana was banned, you know why it should be legalized.

• Author: Sullum, Jacob
• Position: Culture and Reviews - 'Marijuana Legalization: What Everyone Needs to Know' and 'Smoke Signals: A Social History of Marijuana--Medical, Recreational, and Scientific' - Book review

Marijuana Legalization: What Everyone Needs to Know, by Jonathan P. Caulkins, Angela Hawken, Beau Kilmer, and Mark A.R. Kleiman, Oxford University Press, 266 pages, $16.95 paper

Smoke Signals: A Social History of Marijuana--Medical, Recreational, and Scientific, by Martin A. Lee, Scribner, 519 pages, $35

IN NOVEMBER, voters in Colorado and Washington approved groundbreaking ballot initiatives legalizing marijuana for recreational use. The measures immediately eliminated penalties for possessing up to an ounce and required state regulators to adopt rules for commercial production and sale by next July in Colorado and next December in Washington. Meanwhile, recent national surveys put support for legalization at 50 percent or more--the highest numbers ever recorded.

In this context of unprecedented public receptiveness to repealing cannabis prohibition, four centrist drug policy specialists--Jonathan Caulkins of Carnegie Mellon, Angela Hawken of Pepperdine, Beau Kilmer of the RAND Corporation, and Mark Kleiman of UCLA--have published Marijuana Legalization, a handy little paperback that aims to tell us "What Everyone Needs to Know" about the subject. Assiduously dedicated to a utilitarian, just-the-facts approach, Caulkins and his co-authors consider marijuana's benefits as well as its hazards, the harm caused by prohibition as well as the harm it prevents, the impact that legalization is apt to have not only on pot smoking but also on drinking, and the fiscal advantages, in terms of new tax revenue and lower law enforcement costs, of treating marijuana more like alcohol.

Along the way, they offer calm and generally fair-minded excursions into controversies such as the perils of increasing pot potency, the alleged link between cannabis and schizophrenia, and the extent to which marijuana prohibition enriches Mexican drug cartels. But after all this judicious weighing of costs and benefits, the authors conclude that the question of whether to legalize marijuana hinges on how you feel about getting high.

"In the end," Cualkins et al. write, "all the fancy benefit-cost analysis boils down to a rather simple proposition. ... If you think marijuana intoxication is, on average, a good thing--counting both the happy controlled users and the unhappy dependent users--then a benefit-cost analysis done in a way that reflects your values will probably conclude that legalization improves social welfare. If you think marijuana intoxication is, on average, a bad thing, then an analysis that reflects your values will probably conclude that legalization harms social welfare--because the dominant outcome of legalization will be more marijuana use."

Although Caulkins and his colleagues do not put it this way, the implication is that the war on marijuana, ostensibly aimed at promoting public health and safety, is fundamentally a matter of taste. It is not even a moral crusade, strictly speaking, since there is no moral principle underlying the arbitrary legal distinction between marijuana and alcohol, which Hawken, in a separate essay toward the end of the book, concedes "makes no sense." As Martin Lee shows in Smoke Signals, his engaging and illuminating new history, marijuana's contraband...