When everyone agrees on something, it is probably time to ask whether everyone might be wrong. In the wake of the Libor-rigging scandal at Barclays (which is so far valiantly carrying the can for all miscreants) and the trading losses at JP Morgan, the clamour for universal banks to be broken up has reached a crescendo.

This, the cacophony argues, should either take the form of a full Glass-Steagall-style separation or the ring-fencing of the banks' retail and small business banking arms to protect them from their nastier and larger investment banking cousins.