Judge US presidential candidates by economic policy skills

BACK in 2008, one of the advertisements that Hillary Clinton ran during the contest for the Democratic nomination featured an imaginary scene in which the White House phone rings at 3 am with news of a foreign crisis, and asked: "Who do you want answering that phone?" It was a fairly mild jab at Barack Obama's lack of foreign policy experience.

As it turned out, once in office, Mr Obama, a notably coolheaded type who listens to advice, handled foreign affairs pretty well - or at least that's how I see it. But asking how a would-be president might respond to crises is definitely fair game.

And military emergencies are not the only kind of crisis to worry about. That 3 am call is one thing; …