This will mean going beyond the Maastricht logic of national responsibility for fiscal and structural policies, and committing to governance arrangements that are actually enforceable – for instance, allowing for intervention rights by the center to prevent unsound national budgets. Sharing sovereignty implies a number of other changes to euro area governance.
First, there have to be strong institutions in order to exercise that sovereignty effectively. This will require a stronger Eurogroup. Second, those European institutions have to be properly democratically legitimated. This requires changes in the way the citizens participate in the European political process, in particular via the European Parliament.