{"ID":2885210,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2508.05340","arxiv_id":"2508.05340","title":"Pairwise efficiency and monotonicity imply Pareto efficiency in (probabilistic) object allocation","abstract":"We consider object allocation problems with capacities (see, e.g., Abdulkadiroglu and Sonmez, 1998; Basteck, 2025) where objects have to be assigned to agents. We show that if a lottery rule satisfies ex-post non-wastefulness and probabilistic (Maskin) monotonicity, then ex-post pairwise efficiency is equivalent to ex-post Pareto efficiency. This result allows for a strengthening of various existing characterization results, both for lottery rules and deterministic rules, by replacing (ex-post) Pareto efficiency with (ex-post) pairwise efficiency, e.g., for characterizations of the Random Serial Dictatorship rule (Basteck, 2025), Trading Cycles rules (Pycia and Unver, 2017), and Hierarchical Exchange rules (Papai, 2000).","short_abstract":"We consider object allocation problems with capacities (see, e.g., Abdulkadiroglu and Sonmez, 1998; Basteck, 2025) where objects have to be assigned to agents. We show that if a lottery rule satisfies ex-post non-wastefulness and probabilistic (Maskin) monotonicity, then ex-post pairwise efficiency is equivalent to ex-...","url_abs":"https://arxiv.org/abs/2508.05340","url_pdf":"https://arxiv.org/pdf/2508.05340v1","authors":"[\"Tom Demeulemeester\",\"Bettina Klaus\"]","published":"2025-08-07T12:41:46Z","proceeding":"econ.TH","tasks":"[\"econ.TH\",\"cs.GT\"]","methods":"[]","has_code":false}