Multi-Level Constitutions
Many constituencies try to restrict uncontrolled centralization by constitutional rules. These rules are often not as consensual as in the model of Buchanan and Tullock, but exempt from day-to-day politics so that they can only be changed by consent of a qualified majority.
Theory and practice of public choice have developed several models to restrict or at least to channel centralization, three of which are of importance: the model of an association of states, the model of a federal state and the model of a unitary state (Blankart 2011).In an association of states a motion to centralize an issue from a lower to a higher level of government is only adopted if it obtains a “gross majority”, that is, if it is adopted by a majority of each member state according to its constitution. In a unitary state a “net majority” of all citizens, independent of their place of residence, is sufficient to centralize an issue. A federal state usually requires a qualified majority somewhere between a gross and net majority. The European Union (EU) is an association of states, the United States and Germany are federal states, and France is a unitary state. Therefore a centralization of government is more likely in the unitary state of France than in an association of states as the EU. On the other hand, it may be more difficult to control the decisions of governments of an association of states than the government of a unitary state, so that an association of states is not exempt from the danger of over-centralization.