It's the end of an era. Former chair of the Federal Reserve Alan Greenspan's urbane outlook and exuberant approach to economics, has been usurped by hometown billionaire Warren Buffett, whose corn-fed approach to investment has always seemed stodgy even as it made him the richest man in the world.

For the 18 years that Alan Greenspan presided over the Federal Reserve, he was the darling of financial markets. Bob Woodward's biography Maestro celebrates how Greenspan, now 82, led the nation through one of the longest booms in history, expanding the economy and limiting inflation. For many people around the globe, the U.S.-led expansion was a time of increasing consumerism, comfort and security.

Few benefited more from Greenspan's decisions than Buffet, who during this period built his empire, Berkshire Hathaway, to one of the most profitable companies in the world with an average annual increase in value of 20% over the last 20 years and grew his personal wealth to $50 billion.

This fall, in the wake of financial meltdown, both Greenspan and Buffet spoke to Congressional committees. Greenspan, whose philosophy has fallen out of favor, was grilled and pressed and finally forced to concede that he encouraged the stratospheric rise in housing prices by keeping interest rates too low for too long and that he failed to regulate risky mortgage lending.

U.S. Rep Henry Waxman of California, chairman of the House Committee on Oversight and Government Reform, demanded: "Do you feel that your ideology pushed you to make decisions that you wish you had not made?"

And Greenspan conceded: "Yes, I've found a flaw. I don't know how significant or permanent it is. But I've been very distressed by that fact."

Reflecting his new favored status, Buffet's contact with Congress was much more affable. In the midst of negotiations over the $170 billion bailout, the congressional committee negotiating the deal called Warren Buffet at his Nebraska office and asked his advice. The exact exchange wasn't revealed, but the tone of that conversation was apparently totally different from the formal hearing featuring Greenspan. Buffet told PBS' Charlie Rose that he would tell Congress, "This really is an economic Pearl Harbor. That sounds melodramatic, but I've never used that phrase before. And this really is one."

The competition between the Greenspan and Buffet actually began long before the current dust-up.

In 2004, Forbes magazine published a chart showing the two men's views on derivatives such as credit-default swaps. Greenspan extolled their virtues and said that more regulation was unnecessary. Buffet took the opposite view as he did in his 2003 Berkshire Hathaway shareholder letter, where he wrote that derivatives were "financial weapons of mass destruction."

Today, Buffet's views are in and Greenspan's philosophy is out. But only time will prove which man was right.