Stability and Pareto Optimality in Refugee Allocation Matchings

Haris Aziz (UNSW Sydney and Data61), Jiayin Chen (UNSW Sydney and Data61), Serge Gaspers (UNSW Sydney and Data61), Zhaohong Sun (UNSW Sydney and Data61)

Abstract

We focus on the refugee matching problem-a general "two-sided matching under preferences" model with multi-dimensional feasibility constraints. We propose a taxonomy of stability concepts for the problem; identify relations between them; and show that even for two natural weakenings of the standard stability concept, non-existence and NP-hardness results persist. We then identify several natural weaker stability concepts for which we present a polynomial-time and strategy-proof algorithm that returns a stable matching. We also examine the complexity of computing and testing Pareto optimal matchings.