The Complexity of Minimizing Subsidies in Envy-Free House Allocation

2026-08-23

AI Summary

研究通过引入补贴解决公平分配房屋问题，确保无嫉妒分配，并探索了最小化总补贴的计算复杂性及算法。

Abstract

The house allocation problem is a classical one-sided matching problem that concerns the assignment of a set of $m$ houses to $n$ agents according to their preferences, where each agent is assigned exactly one house. Among the various objectives studied in this setting, envy-freeness is one of the most widely adopted fairness criteria. As envy-free house allocations do not always exist, we address this challenge by introducing subsidies and aim to compute allocations that achieve envy-freeness with minimum total subsidy. For binary instances, we show that a total subsidy of at most $(n-1)$ suffices to guarantee envy-freeness in house allocation, and this bound is tight. Building on the known NP-hardness for general utilities, we further show that computing an allocation that minimizes the total subsidy is NP-hard, even under binary utilities. However, when there are only a bounded number of types of agents with binary utilities, the problem can be solved in polynomial time. Finally, we present a polynomial time algorithm that computes the minimum subsidy required to achieve envy-freeness for two types of agents with general utilities.

Problem

• house allocation
• envy-freeness
• subsidies

Innovation

• subsidies
• envy-freeness
• polynomial time algorithm
• binary utilities