 The “Principle of Subsidiarity” has often been used to guide the decisions about allocation of power. This principle has recently received attention owing to its inclusion in European Union treaties. It holds that authority should rest with the member units unless allocating them to a central unit would ensure higher comparative efficiency or effectiveness in achieving certain goals. This principle can be specified in several ways, for instance concerning which units are included, which goals are to be achieved, and who has the authority to apply it. The principle has multiple pedigrees, and came to recent political prominence largely through its role in quelling fears of centralization in Europe—a contested role which the principle has not quite filled (Fleiner and Schmitt 1996, Burgess and Gagnon 1993, Føllesdal 1998).