The Myth of the Explicit Reaction Function’s NecessityCritics of Kevin Warsh’s new approach to monetary policy have fixed upon a strange idol: the reaction function. Calling it a reaction function makes the demand sound scientific and less like Wall Street asking the Fed to hold its hand. A well-understood reaction function can help investors anticipate what the Fed will do before Fed officials tell us. The demand for more explicit talk about the reaction function is just not well-grounded in economic theory or research. All the talk about the reaction function will not make a difference.