Thus, shared sovereignty, aggravated by different preferences and different institutional frameworks and cultures, has imposed the need to identify the required minimum conditions for the functioning of the Monetary Union. This means that the group had to adopt rules not deriving from market sustainability principles, but rather from the need to install and operate self-imposed mutual-trust mechanisms.
The observance of these rules, which I will call constituent rules, is key for the survival and development of the whole, i.e. of the group. Therefore, these rules can only be changed by a decision of the same nature. Compliance with them is fundamental in order not to jeopardise the group.