A drawback of Alan Greenspan's highly successful 18 years at the Federal Reserve is that US monetary policy has become too personalised around the chairman, potentially leading to market trauma after a mere mortal takes over the job, it was suggested on Friday.

“We will soon learn whether the Greenspan era has created a deep reservoir of faith in the Federal Reserve, or just in Alan Greenspan,” said Alan Blinder and Ricardo Reis, of Princeton University, presenting a paper at the Fed's Jackson Hole symposium.