When George W. Bush fired his Treasury secretary and chief economic adviser on Friday, he was signalling to the financial markets not just a change in personnel but a change in economic policy to come. Both Paul O'Neill and Lawrence Lindsey are able men, and were fiercely loyal to the president. Their downfall was a result of the "bumpy performance of the economy" - as President Bush put it - over the past two years and what turned out to be a series of Pollyanna-ish economic forecasts. It was only coincidence, but symbolic nonetheless, that what has come to be...