9 / 14  BIS central bankers' speeches  But the persistence of the effects of the crisis has, at times, challenged the coordinating role of monetary policy. We have faced instances where protracted softness in actual inflation has contributed to a reappraisal of medium to long-term inflation expectations.
You can see this in the grey range moving away from the zero line on the left-hand chart between 2010 and 2015. Forceful monetary policy action has succeeded in restoring the important role that stable inflation expectations play for the inflation process in a heterogeneous currency union.