Should the ECB change monetary policy objective, and what objective should it choose?

For the time being, the ECB’s very expansionary monetary policy has not restored core inflation or expected inflation in the euro zone, which is due to the functioning of both the labour market and the goods and services market. Should this lead the ECB to change its monetary policy objective, and what objective should it choose? If inflation remains permanently lower than 2%, the ECB will be faced with the perils of zero or negative interest rates (bubbles, increasing public debt, multiplication of zombie firms, weakening of banks), which will actually drive it to change its objective; Lowering the inflation target so a new, lower target can be reached would lead to a risk of being able to cut interest rates only very slightly in the event of a recession (with low equilibrium nominal interest rates corresponding to low inflation); Raising the inflation target (or switching to a price level objective) to try to drive up expected inflation (if it is linked to the inflation target or to the gap between the price level target and the current price level) comes up against a credibility problem: the ECB is already now unable to restore expected inflation, investors do not heed its announcements on the inflation level it wants to return to; The last option is then to switch from an inflation objective to a nominal growth objective, which would have many advantages: ability to normalise interest when real growth returns, even without inflation; linking interest rates to income growth, which is what is important.