New Principles for a better EU

We propose the construction of a multi-speed, multi-track and multi-level (MSTL) European Union to replace the present one-speed, one-track and one-level union as a way to increase the flexibility of the process of integration and avoid inter-country conflicts. The paper shows that this general approach is superior, applicable even in the presence of negative spillovers where some refinements may be in order for dealing with fundamental issues like monetary union and immigration.