Prominent people in Washington and on Wall Street say President Barack Obama is starting to focus on what may be the most important appointment of his second term: the next chairman of the Federal Reserve.

Ben Bernanke's term expires in January and he has told associates that the eight challenging years he will have served would be enough. Some people close to the president say his top personal choice to succeed Bernanke would be former Treasury Secretary Tim Geithner. They established a close bond over four years.

Geithner, however, publicly and privately insists that he doesn't want the job, and needs, for personal and financial reasons, more time in New York after years of government service. Even if he's the president's preferred pick, it's uncertain that he would be pressured to take the job; that isn't usually Obama's style.

One remote possibility: Bernanke could be asked to stay for a few more years, until Geithner might be more willing to take the job. It's doubtful the Fed chairman would agree to that, and congressional Republicans would block any deal.

Obama also has great respect for his former top economic adviser, Larry Summers, who is unsurpassed in his knowledge of economic policy, and who would take the job in a minute. His confirmation by the Senate would be an ugly political confrontation, however, and even some Summers fans wonder if his abrasive personality would make it difficult for him to lead the Board of Governors.

If there were an oddsmaker's book, the favorite still would be the current vice chairman, Janet Yellen. She is respected by fellow economists and would likely go over well with markets. One possible hurdle: she clashes frequently with Dan Tarullo, a Fed board member who was an Obama adviser in the 2008 campaign and still has ties to the White House.

A respectable longshot: former vice chairman Roger Ferguson.

This president, like most, loves historic moves. Yellen would be the first woman to head the Fed and Ferguson would be the first black chairman.

(Albert R. Hunt is a Bloomberg View columnist. Follow him on Twitter.)