Economist Mark Perry points out that the Dutch are closing prisons because of a "prisoner shortage." This "decline in crime" was caused by the legalization of drugs. Perry argues that we too could reduce prison populations here by calling a halt to the War on Drugs.
Perry's method for reducing prison populations has great possibilities. In fact, we could eliminate prisons entirely through the simple expedient of legalizing everything.
We could even use this method on other issues. We could increase learning by eliminating things we expect students to know; we could increase quality of life by eliminating qualitative considerations from our measurements of it; we could increase the number of marriages by calling things marriage that are not.
Oh, wait. We've already done these things. Never mind.