For a central bank chief who declared he wanted to make monetary policy boring, Bank of England governor Mervyn King appears to be failing miserably.
The Bank sent markets into a tailspin on Thursday when it raised interest rates to 5.25 per cent, wrongfooting all but one of 50 economists polled by Reuters.
It is not the first time Britain's central bank has sent shockwaves across trading floors. Six months ago the Monetary Policy Committee's decision to tighten policy for the first time in two years also came as a surprise.
"It's the second time the Bank has wrongfooted the markets," said Peter Dixon, economist at Commerzbank. "The Bank is keeping us on our toes."
The forecasters' record has been good in recent years but this wasn't always the case, despite King's declaration in the late 1990s that "policy should be boring and predictable". For instance, in 1999-2001 a majority of economists in Reuters polls wrongly predicted rate decisions no less than six times.
Theories abound on what has caused the Old Lady of Threadneedle Street, as the bank is nicknamed, to act unpredictably on Thursday.
For some people, the Bank was simply girded into action by the strength of economic data and a desire to take pre-emptive action. Above-target inflation, strong house price growth and the threat of a wage-price spiral all argue for tighter monetary policy.
Others think a sneak preview of inflation data may be behind the move. CPI figures for December are not due until next week but were made available to Bank policymakers before the decision.
"Reading between the lines, we suspect that December's inflation print was sufficiently high to persuade the Monetary Policy Committee that an immediate move was necessary," said Richard McGuire at RBC Capital Markets.
Consumer price inflation has been above the two per cent target since May and accelerated to 2.7 per cent in November, its highest since comparable records began a decade ago.
A rise above three per cent would require Prof. King to write a letter to Chancellor of the Exchequer Gordon Brown explaining why inflation was so far off track and what measures were being taken. Such a letter has never been needed since the Bank won independence in 1997 and would inevitably cause a media stir.
Better then to be criticised for a communication failure but at least be seen to be dealing with the situation?
The picture will become clearer on Tuesday. The Office for National Statistics will release December inflation data at 0930 GMT and - if required - an explanatory letter from the Bank must be published within the next hour.