Federal systems (see Federalism) differ greatly in the constitutional structures and powers of the two levels of government. Those in which the central government has preponderant weight, whether in legislative jurisdiction, financial capacity or administrative activity are described as centralized. Those in which the constituent states have great authority or financial capacity display decentralization. There are so many arrangements in existing federations that sure comparison of the result is difficult.
Canada is normally considered to be one of the more decentralized federations although the Constitution Act, 1867 had elements of centralization. For example, the federal government has the power to disallow provincial legislation (see Reservation and Disallowance), a power actively used in the first decades of our federal history but now totally in disuse, and the power to appoint the members of our Senate, a power that is still exercised by the Prime Minister with resulting injury to the representative authority of our second chamber. The modern use of the federal financial strength through its spending power (see federal spending power) has greatly increased the influence of the federal government in areas of provincial jurisdiction without any formal change to our Constitution. As a result, Canada now displays elements of both ‘centralization and decentralization’, while still being one of the most decentralized systems.