A lot is riding on the numbers after the decimal point. In the argot of investors, inflation in America is back to having a “two-handle” (that is, running above 2% but below 3%). It is a far better position to be in than a couple of years ago, when price rises were threatening to hit double digits. But there is a big difference between inflation decelerating towards 2% in the coming year or getting stuck nearer 3%. Not only would the latter forestall aggressive interest-rate cuts by the Federal Reserve, it would also put the central bank on a collision course with Donald Trump—a double-whammy of monetary hawkishness and political turbulence that would cast a shadow over the global economy.