As reported in the Wall Street Journal, the Federal Reserve recently held a retreat in Jackson Hole, WY, for bankers from around the world to discuss the global economic recovery.

Several foreign central bankers said they were struck by the unusual degree of pessimism they had witnessed in the U.S., a contrast to typical American optimism. "I can't wait to get back to my side of the world," said Alan Bollard, governor of the Reserve Bank of New Zealand.

In response to Bernanke's idea to continue "buying long-term bonds to drive long-term interest rates down more", Charles Bean, deputy governor of the Bank of England, said "they were best used only at dire moments. Asset purchases are probably best kept in the locker marked 'For Emergency Use Only.'"

I suppose the British and other European countries know a little bit about "dire moments." Just how low can long-term interest rates go?