The Marijuana Policy Project is touting a study by social-science researcher Jon Gettman that estimates the total cost of marijuana prohibition at about $41.8 billion a year. The estimate includes not only the money spent directly on the drug war -- law enforcement, courts, incarceration, etc., but an estimated $31.1 billion in revenues the gvernment gives up by not taxing the marijuana business normally.
I've talked to Gettman on the phone, when I was researching my book, and he's certainly been trained (PhD in public policy and all that) for this kind of analysis and is plenty smart. I hope the study gets wide publicity. But if most people did rational cost/benefit analysis in their thinking about public policy, we would have ended the war on drugs decades ago. Not only is it expensive, almost all of its results are costs to society rather than benefits. I don't know if that's why it has to be propped up with lies and manufactured fears or if that's just the sloppy way some people approach policy and the kind of irrational politics the people are accustomed to and are willing to tolerate.