Alan W. Bock writing in the Orange County Register has some interesting things to say about how decriminalization in Portugal is going.

Since decriminalization lifetime prevalence rates (any consumption over a lifetime) have decreased, especially for the critical adolescent-young-adult population cohort. For 13-15-year-olds the rate decreased from 14.1 percent in 2001 to 10.6 percent in 2006. For 16-18-year-olds, the lifetime prevalence rate, which had increased from 14.1 percent in 1995 to 27.6 percent in 2001, fell to 21.6 percent in 2006. Perhaps most significantly, heroin use, which officials felt was the most socially destructive drug, fell from 2.5 percent to 1.8 percent from 1999-2005.
The number of drug-related HIV and AIDS cases has declined substantially every year, as have Hepatitis B and C infections and drug-related mortality rates.
When compared with the rest of the EU, usage rates in Portugal, which had been among the highest in Europe, are now among the lowest. Portugal now has the lowest lifetime prevalence for cannabis (marijuana) usage in Europe, 8.2 percent, while in Europe generally it is 25 percent. Portugal has a lifetime rate of 1.6 percent for cocaine, compared to 4 percent for Europe generally.
For whatever bundle of reasons, we should start getting accustomed to the idea that harsh anti-drugs laws are often correlated with a worsening of drug problems and decriminalization with bringing them into manageable bounds. Mr. Greenwald cites a 2008 survey of 17 countries showing that the U.S. had by far the highest level of cocaine use over a lifetime (16.2 percent to second-place New Zealand’s 4.3 percent) and the highest level of cannabis use. As Greenwald writes, “stringent criminalization laws do not produce lower drug usage, and some data suggest the opposite may be true.”

There appear to be second order effects of prohibition (profit to dealers – forbidden fruit) that overwhelm the first order effects such as punishment. It happens.
Mexico recently decriminalized small amounts of most drugs. Alan has some comments on that.

I would add that Mexico makes no provision for acquisition of drugs, which is likely to leave the black market largely undisturbed and still powerful. Decriminalization combined with a determination to end trafficking can leave users still dependent on the black market – as is still the case for all too many medical patients in California. The way to undermine a black market is to allow a white market to emerge.
Nonetheless, Mexico’s move, combined with a court decision in Argentina last week that will have a similar impact on small-time users, has the potential to put a significant dent in the religion of prohibitionism. Now if we can just get politicians in the U.S. to pay attention.

Prohibitionism is a faith based on the idea that prohibiting substance abuse and the substances associated with it will lower the incidence of abuse at relatively low cost. It happens with all faiths, if the disconnect from reality is severe the faith loses ground. As with most sincerely held beliefs – it is the youth who see the Emperor Without Clothes first. After that it is just a matter of the faithful dying off.
H/T Drug Policy Forum of Texas
Cross Posted at Power and Control