This is guaranteed in the current practices by the conditional nature of forward guidance announcements, giving central banks the necessary room to react to unanticipated market and economic developments.
The medium term: eventual exit from unconventional policies Unconventional monetary policy measures have been of the utmost importance to strengthen accommodative monetary policy, and they will continue to be an important policy tool as long as the economy is in troubled waters. Yet it is clear that central bank balance sheets cannot grow forever.