Alan Greenspan (; born March 6, 1926) is an American economist who served as Chairman of the Federal Reserve of the United States from 1987 to 2006. He currently works as a private adviser and provides consulting for firms through his company, Greenspan Associates LLC. First appointed Federal Reserve chairman by President Ronald Reagan in August 1987, he was reappointed at successive four-year intervals until retiring on January 31, 2006, after the second-longest tenure in the position (behind William McChesney Martin).