Contractual Federalism and Strategy-proof Coordination

This paper takes a mechanism design approach to federalism and assumes that local preferences are the private information of local jurisdictions. Contractual federalism is defined as a strategy-proof contract among the members of the federation supervised by a benevolent but not omniscient federal authority. We show that even if the size of the information to be elicited is minimal, the incentive compatibility constraint has a bite in terms of flexibility and welfare. Strategy-proof and efficient federal mechanisms are necessarily uniform. There exists inefficient and non-uniform strategy-proof mechanisms, but they are socially worse than non cooperative decentralization. Federal mechanisms which are neutral and robust to coalition manipulations are equivalent to voting rules on uniform policies.