Why are U-turns inevitably “humiliating”, “damaging” or “panic-induced” when performed by politicians and chief executives of FTSE 100 companies, but generally deemed prudent (if often illegal) manoeuvres when pulled off by cab drivers? Gordon Brown and Sir Fred Goodwin of Royal Bank of Scotland may well have mused on that distinction when trudging along Downing Street this week, but the answer appears simple. Back-benchers and investors value certainty more highly than a few hundred pounds taxed at 10 per cent, or an unwanted opportunity to buy more shares in Royal Bank of Scotland at a 46 per cent discount.

But, arguably, in today’s economic environment, certainty is a more over-
valued commodity than wheat, corn or rice. Behavioural psychologists will say it’s all down to the “expert heuristic”, whereby an outward certainty inflates the perceived credibility of the information being imparted. I would say it’s just because politicians, chief executives – and, for that matter, analysts, fund managers and financial journalists – can’t bring themselves to admit “I’m not sure about this”.