The Federal Reserve recently announced plans to publicize its interest rate expectations. The new approach, according to the Fed, should give investors and businesses a more reliable basis on which to plan. The Fed argues further that people, acting on those plans, will enable monetary policy to have a prompter and more thorough impact on longer-term bond yields and on the overall economy. Reasonable as all this sounds, matters may not go quite as smoothly as the Fed seems to think. On the contrary, the new open approach could cause more harm and more confusion than the former secrecy did.