The scallop, a generally sedentary mollusc, is given to moments of panic when it flaps around like the wind-up false teeth sold in joke shops. A similar spasm is agitating managers at Royal Dutch Shell, which has the shellfish as its emblem. Incoming chief executive Peter Voser told an analysts’ meeting on Thursday: “We have too many people doing business with each other and not with the outside world.” One-fifth of senior executives have already gone.

Mr Voser, a buttoned-down business graduate, has shown impeccable timing in taking on the top job. A bad time for oil companies is a good time to take over running one, particularly a giant as staid as Shell. The weak oil price justifies the gloomy outlook that Mr Voser unveiled Thursday. The likelihood is that the world economy will slowly improve, bolstering profits and his reputation with investors.