Mark Kleiman runs a quick course in illicit-market economics: Reducing demand for marijuana could potentially make the price rise, not fall as would be expected. Good stuff. And indeed, drug prices are always a tricky thing and I don't think I ever quite understand them—if only because the difference between the nominal price and the actual price diverges wildly.

For instance, I could get heroin very cheaply here in San Francisco, in dollar terms, but in reality it's very "expensive" for me to find a dealer, brave the relevant neighborhood, avoid getting caught, and assuming various health risks (it is unregulated after all). Legalizing heroin might well lower the dollar price by a bit, but in reality it would become much, much cheaper for me to use, all things considered. On the other hand, marijuana is different—right now I know full well where to find it, dealers tend to be reliable, there aren't any real health risks (it's not like you can overdose on pot), and since I'm not a minority there's little chance of me getting tossed in jail for minor possession. Legalization would lower the full price for me by only a bit, assuming the nominal price stayed more or less stable. I think. At any rate, I'll be the first to say the War on Drugs is a stupid idea, but arguing against it on the grounds that the dollar price of drugs has declined doesn't seem all that sound. Surely it's raised the actual price for many—the question is whether there are better ways of doing so, which there are.