The main reason it didn't happen was because we were rebounding from the previous recession, and the economy had alot of momentum built up. He makes so many contradictory statements it becomes difficult to understand what the hell he's really thinking. He seems to be trying to control numerous things no previous Fed chairman tried to. About a year ago he made this bizarre statement that productivity might be too high. He recently made a statement that it's his job to keep people uncertain about what he's going to do next.
Most economists think the opposite is true.
In fact, the extreme stock market volatility of recent months is due to uncertainty over what he's going to do next. Never forget those FBI files that were undoubtedly hidden between the stolen sofa cushions on their way out of the White House. By playing yo-yo with interest rates at inopportune time, Greenspan hearlded the October crash of 1987 and actually made Dukakis competitive for a few months. Bush Sr., never a great campaigner to begin with, was forced to go negative to put away an election which should've been slam-dunk. Japan's economy is in a wretched state, despite a low, low interest rate of .15 percent.