What's out: Alan Greenspan. What's in: Warren Buffett.

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.