In the Eurosystem, unconventional measures have allowed us to provide liquidity to market participants and thereby deter deflationary expectations. Moreover, the costs of higher inflation should in no way be underestimated.
Apart from menu costs, these include – as you are all well aware – redistribution effects between, say, borrowers and creditors, as well as the loss of allocative efficiency once the transparency of relative prices has been hampered by the resulting higher volatility of inflation. In addition, most tax systems are far from neutral with respect to the level of inflation.