Janet Yellen during her confirmation hearing earlier this month. She's expected to win Senate approval to take over as head of the Federal Reserve. Brendan Smialowski /AFP/Getty Images hide caption

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Janet Yellen, President Obama's nominee to become the next chairman of the Federal Reserve Board, is sworn in Thursday on Capitol Hill for her confirmation hearing. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

Federal Reserve Board Vice Chairman Janet Yellen is considered a top candidate to replace Ben Bernanke now that Lawrence Summers has withdrawn his name for contention for the Fed's top job. Robert Galbraith/Reuters/Landov hide caption

itoggle caption Robert Galbraith/Reuters/Landov

Citing what he calls an "acrimonious" confirmation process, Lawrence Summers called President Obama to tell him of his decision not to seek the job of Federal Reserve Chairman Sunday. AFP/AFP/Getty Images hide caption

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