Single-Deviation Stability in Additively Separable Hedonic Games with Constrained Coalition Sizes

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Bullinger, Martin, Dunajski, Adam, Elkind, Edith, Gilboa, Matan
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866918160542728192
author Bullinger, Martin
Dunajski, Adam
Elkind, Edith
Gilboa, Matan
author_facet Bullinger, Martin
Dunajski, Adam
Elkind, Edith
Gilboa, Matan
contents We study stability in additively separable hedonic games when coalition sizes have to respect fixed size bounds. We consider four classic notions of stability based on single-agent deviations, namely, Nash stability, individual stability, contractual Nash stability, and contractual individual stability. For each stability notion, we consider two variants: in one, the coalition left behind by a deviator must still be of a valid size, and in the other there is no such constraint. We provide a full picture of the existence of stable outcomes with respect to given size parameters. Additionally, when there are only upper bounds, we fully characterize the computational complexity of the associated existence problem. In particular, we obtain polynomial-time algorithms for contractual individual stability and contractual Nash stability, where the latter requires an upper bound of 2. We obtain further results for Nash stability and contractual individual stability, when the lower bound is at least 2.
format Preprint
id arxiv_https___arxiv_org_abs_2510_12641
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Single-Deviation Stability in Additively Separable Hedonic Games with Constrained Coalition Sizes
Bullinger, Martin
Dunajski, Adam
Elkind, Edith
Gilboa, Matan
Computer Science and Game Theory
Data Structures and Algorithms
We study stability in additively separable hedonic games when coalition sizes have to respect fixed size bounds. We consider four classic notions of stability based on single-agent deviations, namely, Nash stability, individual stability, contractual Nash stability, and contractual individual stability. For each stability notion, we consider two variants: in one, the coalition left behind by a deviator must still be of a valid size, and in the other there is no such constraint. We provide a full picture of the existence of stable outcomes with respect to given size parameters. Additionally, when there are only upper bounds, we fully characterize the computational complexity of the associated existence problem. In particular, we obtain polynomial-time algorithms for contractual individual stability and contractual Nash stability, where the latter requires an upper bound of 2. We obtain further results for Nash stability and contractual individual stability, when the lower bound is at least 2.
title Single-Deviation Stability in Additively Separable Hedonic Games with Constrained Coalition Sizes
topic Computer Science and Game Theory
Data Structures and Algorithms
url https://arxiv.org/abs/2510.12641