Alan Greenspan

The former chairman of the Board of Governors of the Federal Reserve System as well as the Federal Open Market Committee (FOMC), the Fed's principal monetary policymaking body. His tenure at the helm of the Fed lasted 18 years from 1987 until early 2006, when Ben Bernanke replaced him. He was first appointed to the post by then-president Ronald Reagan and kept at the Fed's helm by successors George H.W. Bush, Bill Clinton and President George W. Bush.

Greenspan is the first person to have been appointed to five consecutive terms as the Fed's chairman. He became known for being adept at guiding the Fed's board to consensus on policy issues and his public comments were regarded as so powerful that they could send financial markets sharply in any direction.

He was widely perceived as an inflation hawk, often criticized for focusing more on controlling prices than on achieving full employment. Greenspan also became infamous for his often technical and cautiously worded speeches, and reportedly once mocked his own speaking style during a 1988 speech in which he said, "I guess I should warn you, if I turn out to be particularly clear, you've probably misunderstood what I said."