Weak Stability against Robust Deviations and the Bargaining Set in the Roommate Problem

Abstract

We propose a new solution concept in the roommate problem, weak stability against robust deviations (wSaRD), by weakening a similar concept of Hirata et al. (2021). We identify a common sufficient condition for wSaRD and weak stability of Klijn and Massó (2003). We can always construct a weakly efficient matching satisfying this condition. Consequently, we can always find a wSaRD matching within the bargaining set. This is in contrast with the original, stronger concept of Hirata et al. (2021), which does not always intersect with the bargaining set.