Thomas Sowell has a good WSJ ($) op-ed today in which, as former House Majority Leader Dick Armey — an economist by trade — put it: “Demagoguery beats data in making public policy.” The entire article is well worth reading, but here is a tidbit:

At the state and local levels, this confusion of tax rates and tax revenues has led some local politicians to see higher tax rates as the answer to budget problems, even though higher tax rates can drive businesses out of the city or state, with adverse effects on the total amount of tax revenues collected.
Price controls are another area where very elementary economics is all that is needed to show what the consequences are: shortages, quality deterioration and black markets. It has happened repeatedly in countries around the world, over a period of centuries. Yet politicians keep selling the idea of price controls and voters keeping buying it.
Many economic issues are complex, but sometimes a single fact will tell you all you need to know. When you know that central planners in the Soviet Union had to set 24 million prices — and keep adjusting them, relative to one another, as conditions changed — you realize that central planning did not just happen to fail. It had no chance of succeeding from the outset. It is a wholly different ball game when hundreds of millions of people individually keep track of the relatively few prices they need to know for their own decision-making in a market economy.