Almost Envy-Free Allocations with Connected Bundles

Abstract

We study the existence of allocations of indivisible goods that are envy-free up to one good (EF1), under the additional constraint that each bundle needs to be connected in an underlying item graph. If the graph is a path and the utility functions are monotonic over bundles, we show the existence of EF1 allocations for at most four agents, and the existence of EF2 allocations for any number of agents; our proofs involve discrete analogues of the Stromquist's moving-knife protocol and the Su--Simmons argument based on Sperner's lemma. For identical utilities, we provide a polynomial-time algorithm that computes an EF1 allocation for any number of agents. For the case of two agents, we characterize the class of graphs that guarantee the existence of EF1 allocations as those whose biconnected components are arranged in a path; this property can be checked in linear time.

Accepted journal version

References in corpus (2)

• Fair Division of a Graph
• Pareto-Optimal Allocation of Indivisible Goods with Connectivity Constraints

Cited by in corpus (7)

• The Price of Connectivity in Fair Division
• Fair allocation of a multiset of indivisible items
• Mind the Gap: Cake Cutting With Separation
• Pareto-Optimal Allocation of Indivisible Goods with Connectivity Constraints
• Dividing a Graphical Cake
• Differentially Private Fair Division
• Fair Division with Two-Sided Preferences