English

Shapley-Scarf Markets with Objective Indifferences

Theoretical Economics 2026-02-03 v3

Abstract

Top trading cycles with fixed tie-breaking (TTC) has been suggested to deal with indifferences in object allocation problems. Unfortunately, under general indifferences, TTC is neither Pareto efficient nor group strategy-proof. Furthermore, it may not select an allocation in the core of the market, even when the core is non-empty. However, when indifferences are agreed upon by all agents (``objective indifferences''), TTC maintains Pareto efficiency, group strategy-proofness, and core selection. Further, we characterize objective indifferences as the most general setting where TTC maintains these properties.

Keywords

Cite

@article{arxiv.2503.18144,
  title  = {Shapley-Scarf Markets with Objective Indifferences},
  author = {Will Sandholtz and Andrew Tai},
  journal= {arXiv preprint arXiv:2503.18144},
  year   = {2026}
}