preprints and working papers

2026

1. Axioms for Top Trading Cycles in Multi-Object Reallocation
   (Job Market Paper)

   Jacob Coreno, and Di Feng

   Previously circulated under the title “Some Characterizations of TTC in Multiple-Object Reallocation Problems”
   arXiv preprint arXiv:2404.04822, 2026

   Abs arXiv PDF Slides

   This paper studies multi-object reallocation without monetary transfers, where agents initially own multiple indivisible objects and have strict preferences over bundles (e.g., shift exchange among workers at a firm). Focusing on marginal rules that elicit only rankings over individual objects, we provide axiomatic characterizations of the generalized Top Trading Cycles rule (TTC) on the lexicographic and responsive domains. On the lexicographic domain, TTC is characterized by balancedness, individual-good efficiency, the worst-endowment lower bound, and either truncation-proofness or drop strategy-proofness. On the responsive domain, TTC is the unique marginal rule satisfying individual-good efficiency, truncation-proofness, and either the worst-endowment lower bound or individual rationality. In the Shapley–Scarf housing market, TTC is characterized by Pareto efficiency, individual rationality, and truncation-proofness. Finally, on the conditionally lexicographic domain, the augmented Top Trading Cycles rule is characterized by balancedness, Pareto efficiency, the worst-endowment lower bound, and drop strategy-proofness. The conditionally lexicographic domain is a maximal domain on which Pareto efficiency coincides with individual-good efficiency.

2024

1. Axiomatic Characterizations of Draft Rules

   Jacob Coreno, and Ivan Balbuzanov

   Conditionally accepted at the Journal of Economic Theory
   arXiv preprint arXiv:2204.08300, 2024

   Abs arXiv Slides

   Drafts are sequential allocation procedures for distributing heterogeneous and indivisible objects among agents subject to some priority order (e.g., allocating players’ contract rights to teams in professional sports leagues). Agents report ordinal preferences over objects and bundles are partially ordered by pairwise comparison. We provide a simple characterization of draft rules: they are the only allocation rules which are respectful of a priority (RP), envy-free up to one object (EF1), non-wasteful (NW) and resource monotonic (RM). RP and EF1 are crucial for competitive balance in sports leagues. We also prove three related impossibility theorems showing that the competitive-balance axioms RP and EF1 are generally incompatible with strategy-proofness. However, draft rules satisfy maxmin strategy-proofness. If agents may declare some objects unacceptable, then draft rules are characterized by RP, EF1, NW, and RM, in conjunction with individual rationality and truncation invariance. In a model with variable populations, draft rules are characterized by EF1, EFF, and RM, together with (population) consistency, top-object consistency, and neutrality.

2. Justified Fairness in House Allocation Problems: Two Characterizations of Strategy-proof Mechanisms

   Di Feng, and Jacob Coreno

   arXiv preprint arXiv:2407.14101, 2024

   Abs arXiv

   We consider the house allocation problems with strict preferences, where monetary transfers are not allowed. We propose two properties in the spirit of justified fairness. Interestingly, together with other well-studied properties (strategy-proofness and non-bossiness), our two new properties identify serial dictatorships and sequential dictatorships, respectively.

publications

2025

1. Characterizing TTC via endowments-swapping-proofness and truncation-proofness

   Jacob Coreno, and Di Feng

   Economics Letters, 2025

   Abs PDF Website

   In the object reallocation problem introduced by Shapley and Scarf (1974), Fujinaka and Wakayama (2018) showed that Top Trading Cycles (TTC) is the unique rule satisfying individual rationality, strategy-proofness, and endowments-swapping-proofness. We show that the uniqueness remains true if strategy-proofness is weakened to truncation-proofness.