Supply and demand
Outside of drug policy, M. Simon of Power and Control and I are pretty far apart politically. Nonetheless, I like his no nonsense approach and I'm a big fan of his blog. He favors us with an interesting lesson on supply side economics and the black market in drugs. Simon also makes a good point on the effect of prohibition on the market.

Cross border importation has given way to hydroponic homegrown. Ever notice how many hydroponic stores are in your town? Our small town just added another a year ago. Prices will start to fall in time even in the marijuana market.

Ironically, since no major government/corporate entities are involved on the supply side, as there are on the prohibition end of the equation - the drug market may realistically be called the free market's greatest success.