The random stable roommates problem typically has no solution

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Authors: Byron Chin, Marcus Michelen
Cited by: 0

Abstract

Assume that $n = 2k$ potential roommates each have an ordered preference of the $n-1$ others. A stable matching is a perfect matching of the $n$ roommates in which no two unmatched people prefer each other to their matched partners. In their seminal 1962 stable marriage paper, Gale and Shapley noted that not every instance of the stable roommates problem admits a stable matching. In the case when the preferences are chosen uniformly at random, Gusfield and Irving predicted in 1989 that there is no stable matching with high probability for large $n$. We prove this conjecture and show that for $n$ sufficiently large, the probability there is a stable matching is at most $n^{-1/17}$.

Fields of Study & Subjects

Game Theory and Voting Systems Constraint Satisfaction and Optimization Optimization and Search Problems

Publication details

Journal / source
arXiv (Cornell University)
Publication date
12 January 2026
Document type
Preprint