Cross-monotonic cost sharing methods for connected facility location games

We present cost sharing methods for connected facility location games that are cross-monotonic and competitive and that recover a constant fraction of the cost of the constructed solution. The novelty of this paper is that we use randomized algorithms and that we share the expected cost among the participating users. As a consequence, our cost sharing methods are simple and achieve attractive approximation ratios. We also provide a primal-dual cost sharing method for the connected facility location game with opening costs. (C) 2004 Elsevier B.V. All rights reserved.