To answer this question, it is helpful to use economic forecasts, market-implied expectations, and econometric models to assess where real interest rates are expected to be in the longer run, and compare them with the levels that prevailed in the decades before the crisis.
Only the spread of inflation rates remains close to being within the Maastricht range [Chart 4] – a tribute of course to it being the target of ECB policy. In a way, that last slide is quite instructive in showing the capacity of the monetary union to achieve what was, after all, set by Treaty as its over-arching goal, namely price stability.