As is evident from the demand equation the situation where current and expected output is at its flexible-price level is accompanied by the actual real interest rate being equal to its natural counterpart and thus by a closed interest rate gap.
This obsession is driven by two interrelated observations: First, high levels of public debt harbour the risk of higher inflation. Second, sooner or later high levels of public debt are bound to hurt economic growth. Given the high levels of public debt in many European countries, one would expect a broad consensus in favour of consolidation – and not just among fixated central bankers.