Meina Takahashi
Abstract
We extend the concept of priority-neutral matching, introduced by Reny (2022) in the school choice context, to the roommate problem. We prove three main results. First, a blocking-neutral matching always exists in constrained roommate problems under arbitrary feasibility constraints (Theorem 1). Second, the set of stable matchings is contained in the set of blocking-neutral matchings, which in turn is contained in the set of Pareto-optimal matchings (Theorem 2). Third, whenever stable matchings exist, the set of blocking-neutral matchings coincides with the set of stable matchings (Theorem 3). We also show that existence fails under weak preferences and extend the concept to two-sided school choice.