Paul Krugman has already had to walk back his prediction of a global recession following Donald Trump’s presidential victory last night. His initial post on the New York Times’ website was confidently apocalyptic about the prospects of Donald Trump plunging the world into a depression: “If the question is when markets will recover, a first-pass answer is never.” He concluded by saying, “So we are very probably looking at a global recession, with no end in sight. I suppose we could get lucky somehow. But on economics, as on everything else, a terrible thing has just happened.” Markets rebounded in...