English

On one generalization of stable allocations in a two-sided market

Combinatorics 2025-04-29 v1

Abstract

In the stable allocation problem on a two-sided market introduced and studied by Baiou and Balinski in the early 2000's, one is given a bipartite graph G=(V,E)G=(V,E) with capacities bb on the edges (``contracts'') and quotas qq on the vertices (``agents''). Each vertex vVv\in V is endowed with a linear order on the set EvE_v of edges incident to vv, which generates preference relations among functions (``contract intensities'') on EvE_v, giving rise to a model of \it{stable allocations} for GG. This is a special case of Alkan-Gale's stability model for a bipartite graph with edge capacities in which, instead of linear orders, the preferences of each ``agent'' vv are given via a choice function that acts on the box {zR+Ev ⁣:z(e)b(e),eEv}\{z\in{\mathbb R}_+^{E_v}\colon z(e)\le b(e),\, e\in E_v\} or a closed subset in it and obeys the (well motivated) axioms of consistence, substitutability and cardinal monotonicity. By central results in Alkan-Gale's theory, the set of stable assignments generated by such choice functions is nonempty and forms a distributive lattice. In this paper, being in frameworks of Alkan-Gale's model and generalizing the stable allocation one, we consider the situation when the preferences of ``agents'' of one side (``workers'') are given via linear orders, whereas the ones of the other side (``firms'') via integer-valued choice functions subject to the three axioms as above, thus introducing the model of \it{generalized allocations}, or g-allocations for short. Our main aims are to characterize and efficiently construct rotations, functions on EE associated with immediately preceding relations in the lattice (S,)(S,\prec) of stable g-allocations, and to estimate the complexity of constructing a poset generated by rotations for which the lattice of closed functions is isomorphic to (S,)(S,\prec), obtaining a ``compact'' representation of the latter.

Keywords

Cite

@article{arxiv.2504.19978,
  title  = {On one generalization of stable allocations in a two-sided market},
  author = {Alexander V. Karzanov},
  journal= {arXiv preprint arXiv:2504.19978},
  year   = {2025}
}

Comments

35 pages, 2 fig