Fair Allocation of Indivisible Goods with Variable Groups

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gölz, Paul, Igarashi, Ayumi, Manurangsi, Pasin, Suksompong, Warut
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911255821811712
author Gölz, Paul
Igarashi, Ayumi
Manurangsi, Pasin
Suksompong, Warut
author_facet Gölz, Paul
Igarashi, Ayumi
Manurangsi, Pasin
Suksompong, Warut
contents We study the fair allocation of indivisible goods with variable groups. In this model, the goal is to partition the agents into groups of given sizes and allocate the goods to the groups in a fair manner. We show that for any number of groups and corresponding sizes, there always exists an envy-free up to one good (EF1) outcome, thereby generalizing an important result from the individual setting. Our result holds for arbitrary monotonic utilities and comes with an efficient algorithm. We also prove that an EF1 outcome is guaranteed to exist even when the goods lie on a path and each group must receive a connected bundle. In addition, we consider a probabilistic model where the utilities are additive and drawn randomly from a distribution. We show that if there are $n$ agents, the number of goods $m$ is divisible by the number of groups $k$, and all groups have the same size, then an envy-free outcome exists with high probability if $m = ω(\log n)$, and this bound is tight. On the other hand, if $m$ is not divisible by $k$, then an envy-free outcome is unlikely to exist as long as $m = o(\sqrt{n})$.
format Preprint
id arxiv_https___arxiv_org_abs_2511_06218
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fair Allocation of Indivisible Goods with Variable Groups
Gölz, Paul
Igarashi, Ayumi
Manurangsi, Pasin
Suksompong, Warut
Computer Science and Game Theory
Discrete Mathematics
Probability
We study the fair allocation of indivisible goods with variable groups. In this model, the goal is to partition the agents into groups of given sizes and allocate the goods to the groups in a fair manner. We show that for any number of groups and corresponding sizes, there always exists an envy-free up to one good (EF1) outcome, thereby generalizing an important result from the individual setting. Our result holds for arbitrary monotonic utilities and comes with an efficient algorithm. We also prove that an EF1 outcome is guaranteed to exist even when the goods lie on a path and each group must receive a connected bundle. In addition, we consider a probabilistic model where the utilities are additive and drawn randomly from a distribution. We show that if there are $n$ agents, the number of goods $m$ is divisible by the number of groups $k$, and all groups have the same size, then an envy-free outcome exists with high probability if $m = ω(\log n)$, and this bound is tight. On the other hand, if $m$ is not divisible by $k$, then an envy-free outcome is unlikely to exist as long as $m = o(\sqrt{n})$.
title Fair Allocation of Indivisible Goods with Variable Groups
topic Computer Science and Game Theory
Discrete Mathematics
Probability
url https://arxiv.org/abs/2511.06218