First of all, the dynamics of globalisation have certainly made the central banks’ task of analysing the inflation process more complicated. This may have caused potential output, which is a crucial input for the economic analysis of risks to price stability, to have been overestimated.
Prior to the GFC there was a school of thought that because asset price bubbles could not be detected in advance, it was better to clean up after any bust, rather than lean against the cycle with policy.