A police officer keeps watch outside the Federal Reserve headquarters in Washington, D.C., where policymakers weighed whether to boost interest rates. Kevin Lamarque/Reuters/Landov hide caption

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Federal Reserve Chair Janet Yellen, speaking at a news conference in Washington on Thursday, said the U.S. economy has been performing well but the global outlook is more uncertain. Jacquelyn Martin/AP hide caption

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Federal Reserve Chair Janet Yellen testifies before the Senate Banking Committee in July. This week, Yellen and other policymakers are weighing the Fed's first rate increase in nine years. Susan Walsh/AP hide caption

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Federal Reserve Chair Janet Yellen and other policymakers will meet in Washington, D.C., this week to weigh a possible increase in interest rates. Manuel Balce Ceneta/AP hide caption

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Federal Reserve Vice Chairman Stanley Fischer speaks during a Board of Governors of the Federal Reserve System meeting in July. Manuel Balce Ceneta/AP hide caption

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A Chinese worker is seen at a construction site in Beijing. Economic changes in China and in other places have reduced demand and prices for commodities like the metal in the building's structure. AP hide caption

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Jason Furman, chairman of the White House Council of Economic Advisers, said consumers generally haven't been using the savings from lower gasoline prices to spend on other things. Justin Sullivan/Getty Images hide caption

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Earlier this year, the European Central Bank, headed by Mario Draghi, launched a bond-buying program to drive down interest rates and boost borrowing. Emmanuel Dunand/AFP/Getty Images hide caption

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Target shoppers Kelly Foley (from left), Debbie Winslow and Ann Rich use a smartphone to look at a competitor's prices while shopping shortly after midnight on Black Friday, in South Portland, Maine. Robert F. Bukaty/AP hide caption

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A New York Stock Exchange trader works on the floor on Dec. 17. Stocks rose nearly 300 points after the Federal Reserve announced it plans to begin raising interest rates next year. Andrew Burton/Getty Images hide caption

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Mario Draghi, president of the European Central Bank. Some say he's super. Daniel Reinhardt /DPA/LANDOV hide caption

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Federal Reserve Chairman Ben Bernanke during a news conference in June. Financial markets reacted to comments he made then by selling off bonds and stocks. Alex Wong/Getty Images hide caption

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Monument to headier times: The euro logo outside the European Central Bank in Frankfurt. The International Monetary Fund has warned of possible deflation in parts of Europe. Frank Rumpenhorst/AFP/Getty Images hide caption

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