Hinata Kurashita | Searcharxiv

arXiv2026

The lattice structure of the crawler

We study object reallocation problems with single-peaked preferences. On the unrestricted domain of strict preferences, top trading cycles (TTC) is the unique rule that satisfies efficiency, individual rationality, and strategy-proofness. On the single-peaked preference domain, the crawler introduced by Bade (2019) satisfies the same properties. We show that the Nash equilibrium allocations of the crawler's direct revelation game form a complete lattice under weak Pareto dominance. The truthful allocation is the greatest element of this lattice, while the initial endowment allocation is its least element.

econ.TH↗

arXiv2026

Egalitarian-equivalent and strategy-proof mechanisms in homogeneous multi-object allocation problems

We study the problem of allocating homogeneous indivisible objects among agents with money. In particular, we investigate the relationship between egalitarian-equivalence (Pazner and Schmeidler, 1978), as a fairness concept, and efficiency under agents' incentive constraints. As a first result, we characterize the class of mechanisms that satisfy egalitarian-equivalence, strategy-proofness, individual rationality, and no subsidy. Our characterization reveals a strong tension between egalitarian-equivalence and efficiency: under these properties, objects are allocated only in limited cases. To address this limitation, we replace strategy-proofness with the weaker incentive property non-obvious manipulability (Troyan and Morrill, 2020). We show that this relaxation allows us to design mechanisms that achieve efficiency while still ensuring egalitarian-equivalence. Furthermore, under efficiency, we identify the agent-welfare-optimal mechanism in the characterized class.

econ.TH↗