It is good for accountability: the public opinion can judge whether or how we are achieving our own goals in comparison with the yardstick we made public. It is good for medium and long-term credibility: inflationary expectations can be more easily anchored.
Let me also recall that the success of the transition to the Euro five years ago demanded as much clarity as possible as regards our definition of price stability in comparison with previous national definitions of price stability. We had promised that the new currency would be at least as good as the previous national currencies.