Public goods provision: Unit-by-unit cost-sharing rules and the core

In a simple model of one public good producible from one input, we show that unit-by-unit cost-sharing rules have two properties. First, a unit-by-unit cost-sharing rulealways chooses a core allocation. Second, every allocation in the core will be chosen by at least one unit-by-unit cost-shring rule. We argue that costs should be shared on a unit-by-unit basis. We propose a simple mechanism to implement the family of unit-by-unit rules. Received: 18 May 2005, Accepted: 6 December 2005 JEL Classification: H41, C72, D78 I thank Hervé Moulin for helpful comments and discussions. All errors are mine. Financial support from the Hong Kong Research Grants Council under grant RGC-DAG99/00.BM52 is gratefully acknowledged.