An important stylized fact to emerge from the VAR estimates is that exogenous monetary policy shocks (also labelled unsystematic monetary policy) have a delayed, persistent, hump shaped effect on in.ation. I argue that this empirical pattern is fragile. In particular it disappears when one...

This paper extends the New Keynesian model to allow for stochastic shifts in the monetary policy regime. Agents cannot observe the regime and use a Bayesian learning rule to make optimal inferences. Price setting is adapted to this environment: lagged expectations about monetary policy influence...