Monetary union creates deep integration between its member countries and, as such, a high degree of mutual vulnerability. We have therefore always applied the principle that if policies in one country can have large effects on others, they have to be governed by common rules or institutions.
This is why we have the fiscal framework, for example, as a default in one country would cause damage to all its partners. And I think it is now clear that the principle should also apply to structural policies because a low growth potential creates macroeconomic imbalances between the countries. The vulnerability which derives from this affects the other countries of the euro area.