[O]pen and clear communication by the policy committee--which in practice includes speeches and congressional testimony by FOMC members, as well as official statements--makes monetary policy more effective in at least three distinct ways.
First, in the very short run, clear communication helps to increase the near-term predictability of FOMC rate decisions, which reduces risk and volatility in financial markets and allows for smoother adjustment of the economy to rate changes...
Second, in the long run, communicating the central bank's objectives and policy strategies can help to anchor the public's long-term expectations--most importantly, its expectations of inflation...
The third way in which clear and open communication enhances the effectiveness of monetary policy--the channel that will be the focus of my remarks today--is by helping to align financial-market participants' expectations about the future course of monetary policy more closely with the policy committee's own plans and projections. As I will discuss, to the extent that central bank talk provides useful guidance to markets about the likely future path of short-term interest rates, policymakers will exert greater influence over the longer-term interest rates that most matter for spending decisions. At the same time, expanding the information available to financial-market participants improves the efficiency and accuracy of asset pricing. Both of these factors enhance the effectiveness and precision of monetary policy.