First and foremost, central banks have realized that open and transparent communication enhances policy effectiveness by way of achieving expected outcomes. This shift in central bank theology from deliberate obscurity to greater transparency actually reflects a shift in the theory of monetary policy.
Up until the early 1990s, monetary policy was strongly influenced by Nobel Laureate Robert Lucas’ argument that monetary policy affected real variables, like growth, only if the policy changes were unanticipated. This encouraged obscurity over openness and clarity. However, lost in the message was that monetary policy always affected nominal variables like inflation even if fully anticipated.