Mr. Ben Bernanke has been selected by U.S. President George W. Bush to head the Federal Reserve Board. Mr. Bernanke will succeed Mr. Alan Greenspan, a man many consider the most successful central banker in U.S. history. Those are big shoes to fill, yet he must succeed: The Fed chairman is perhaps the most important banker in the world. International economic stability and prosperity depend on his ability to steer the U.S. economy with a steady hand, to anticipate troubles, and to respond quickly and effectively to crises when they do break out.

Mr. Bernanke is certainly qualified for the new job. At the time of his nomination, he was chairman of the president's Council of Economic Advisers. He got a firsthand glimpse of how the Fed works and was able to watch Mr. Greenspan up close when Mr. Bernanke was a member of the Fed's policymaking board from August 2002 until June 2005. But the nominee received most of his experience in academia: He served as chairman of Princeton's economics department, and is best known for his research into the Federal Reserve's role during the Great Depression. Hopefully, he will not have to draw too deeply on that work.

His academic focus has made some Fed watchers nervous. They worry that a good governor needs more than an academic understanding of markets. Mr. Greenspan was an economic forecaster before he became Fed chairman nearly two decades ago. His predecessor, Mr. Paul A. Volker, ran the New York branch of the Federal Reserve. Both men worked with the capitalists and financiers, and were able to understand and assess all the forces that move markets.