For monetary policy this does not mean, however, that we will inevitably and over-hastily return to the limited set of instruments and the balance sheet size of the pre-crisis period. Regulatory changes and the enduring fragmentation of European financial markets may in the future require some adjustments to our operational framework for monetary policy within our well-established strategy.
However, whatever a future monetary policy framework may look like, it must be based exclusively on the price stability mandate and set up within legal limits. 1 Costs of inflation include the sub-optimal allocation of goods and activities, so-called shoe leather costs,  distortions to the tax system and costs associated with the de-anchoring of inflation expectations.