Approximately Efficient CostSharing Mechanisms
Abstract
We make three different types of contributions to costsharing: First, we identify several new classes of combinatorial cost functions that admit incentivecompatible mechanisms achieving both a constantfactor approximation of budgetbalance and a polylogarithmic approximation of the social cost formulation of efficiency. Second, we prove a new, optimal lower bound on the approximate efficiency of every budgetbalanced Moulin mechanism for Steiner tree or SSRoB cost functions. This lower bound exposes a latent approximation hierarchy among different costsharing problems. Third, we show that weakening the definition of incentivecompatibility to strategyproofness can permit exponentially more efficient approximately budgetbalanced mechanisms, in particular for set cover costsharing problems.
 Publication:

arXiv eprints
 Pub Date:
 June 2006
 arXiv:
 arXiv:cs/0606127
 Bibcode:
 2006cs........6127R
 Keywords:

 Computer Science  Computer Science and Game Theory;
 F.2.0
 EPrint:
 latex source, 22 pages, 1 figure