Computational Complexity of the Hylland-Zeckhauser Scheme for One-Sided Matching Markets
Computational Complexity of the Hylland-Zeckhauser Scheme for One-Sided Matching Markets
复制标题
DOI:
10.4230/lipics.itcs.2021.59
复制
发表时间:
2020-04
期刊:
影响因子:
--
通讯作者:
V. Vazirani;M. Yannakakis
中科院分区:
文献类型:
--
作者:
V. Vazirani;M. Yannakakis
In 1979, Hylland and Zeckhauser \cite{hylland} gave a simple and general scheme for implementing a one-sided matching market using the power of a pricing mechanism. Their method has nice properties -- it is incentive compatible in the large and produces an allocation that is Pareto optimal -- and hence it provides an attractive, off-the-shelf method for running an application involving such a market. With matching markets becoming ever more prevalant and impactful, it is imperative to finally settle the computational complexity of this scheme. We present the following partial resolution: 1. A combinatorial, strongly polynomial time algorithm for the special case of $0/1$ utilities. 2. An example that has only irrational equilibria, hence proving that this problem is not in PPAD. Furthermore, its equilibria are disconnected, hence showing that the problem does not admit a convex programming formulation. 3. A proof of membership of the problem in the class FIXP. We leave open the (difficult) question of determining if the problem is FIXP-hard. Settling the status of the special case when utilities are in the set $\{0, {\frac 1 2}, 1 \}$ appears to be even more difficult.