The Greenspan Put is a term academics, journalists, and others use to describe a practice instituted by the late former Federal Reserve Chair Alan Greenspan that has become part of the central bank’s tools of monetary policy.It was supposed to be an aid to markets in dark times, changing the face of the economy for the better. But it has really been a tool for bettors, the big investors who want to feel that someone will have their backs when things go wrong. The Put also undermines the basic idea of markets, that some things will succeed, others fail, and…