The Price of Optimum: Complexity and Approximation for a Matching Game
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- 作者：Bruno Escoffier ; Laurent Gourvès ; Jérôme Monnot
- 关键词：Approximation algorithm ; Srategic game ; Complexity ; Price of Anarchy ; Price of optimum ; Stackelberg strategy
- 刊名：Algorithmica
- 出版年：2017
- 出版时间：March 2017
- 年：2017
- 卷：77
- 期：3
- 页码：836-866
- 全文大小：
- 刊物类别：Computer Science
- 刊物主题：Algorithm Analysis and Problem Complexity; Theory of Computation; Mathematics of Computing; Algorithms; Computer Systems Organization and Communication Networks; Data Structures, Cryptology and Inform
- 出版者：Springer US
- ISSN：1432-0541
- 卷排序：77
文摘
This paper deals with a matching game in which the nodes of a simple graph are independent agents who try to form pairs. If we let the agents make their decision without any central control then a possible outcome is a Nash equilibrium, that is a situation in which no unmatched player can change his strategy and find a partner. However, there can be a big difference between two possible outcomes of the same instance, in terms of number of matched nodes. A possible solution is to force all the nodes to follow a centrally computed maximum matching but it can be difficult to implement this approach. This article proposes a tradeoff between the total absence and the full presence of a central control. Concretely, we study the optimization problem where the action of a minimum number of agents is centrally fixed and any possible equilibrium of the modified game must be a maximum matching. In algorithmic game theory, this approach is known as the price of optimum of a game. For the price of optimum of the matching game, deciding whether a solution is feasible is not straightforward, but we prove that it can be done in polynomial time. In addition, the problem is shown APX-hard, since its restriction to graphs admitting a perfect matching is equivalent, from the approximability point of view, to vertex cover. Finally we prove that this problem admits a polynomial 6-approximation algorithm in general graphs.