'I have concluded that an ... attempt to provide forward guidance in the policy statement causes more communications difficulties than it solves,' Mr Poole said a speech to the St Louis chapter of the National Association for Business Economics.

'A key reason is that the economy is subject to more shocks and reversals than one might think.'

Mr Poole did not touch on the outlook for the US economy or interest rates in his remarks.

The St Louis Fed president, who retires at the end of March, said he questions the effectiveness of trying to provide guidance about future central bank moves because the economy is subject to many shocks and reversals.

Those shocks require the central bank to change interest rates more frequently that he would have thought likely before he arrived at the regional Fed bank 10 years ago, he said.

Furthermore, language about direction tends to take on a life of its own, Mr Poole said.

When the Fed talks about likely future directions of monetary policy in its statements, that language tends to remain in Fed statements beyond the time it applies, while removing it runs the risk of miscommunication, he said.

'Every change in the policy statement naturally leads to market questions as to what the change means and whether the change is meant to provide a hint about the future direction of policy,' he said. -- REUTERS