"While the Fed Chairman has shown little sign that ideology affects his monetary decisions, he is a very conservative figure and former adviser to Republican presidents. Barney Frank, Democratic congressman and one of Mr. Greenspan,s more thoughtful critics on the Hill, argues that the combination of Mr. Greenspan,s public role and personal beliefs can cause some problems.

The Federal Reserve chairman speaks first and foremost as head of the central bank, seeking to promote its policy goals.

But, says Mr. Frank, Mr. Greenspan sees it as his role to maintain good relations with the White House to protect the Fed,s independence and prevent political meddling. Third, he says, the Fed chairman "is a deeply and philosophically conservative guy".