It cannot be an unusual evening at Stringfellows, the West End lap-dancing club, that finds an investment banker, drunk, sitting on his hands, beholding a half-naked woman gyrating before him with a wad of what were until recently his £20 notes festooning her garter belt and asking himself the pressing question of the day: “Do we bankers earn too much?”

It is difficult to pursue a line of rational thought under such circumstances. That is their purpose. Which is a shame, because the answer to the question of bankers’ pay can be found by a close examination of lap dancers — or, at least, of the way they are paid.