AI 中文总结
本文研究当机构选择函数满足强可观测替代性时累积要约机制的性质，证明其多项性质可刻画强OS，且强OS能将COM的弱群体策略完备性简化为个体策略完备性，但该简化不依赖强OS。
AI 中文摘要
当机构的选择函数满足强可观测替代性（strong OS）时，我们研究累积要约机制（COM）的性质。首先，我们证明COM的以下每项性质都可刻画强OS：IR单调性、弱Maskin单调性以及剔除单调性。剔除单调性是比弱Maskin单调性更弱的新条件，可解释为策略完备性和非独裁性的弱化。其次，我们证明当选择函数为强OS时，COM的弱群体策略完备性可简化为个体策略完备性，但强OS对该简化既非必要也非“几乎必要”。
英文摘要
We study the properties of the cumulative offer mechanism (COM) when institutions' choice functions satisfy strong observable substitutability (strong OS). First, we show that each of the following properties of the COM characterizes strong OS: IR monotonicity, weak Maskin monotonicity, and dropping monotonicity. Dropping monotonicity is a new condition weaker than weak Maskin monotonicity, and it is interpretable as a weakening of strategy-proofness and non-bossiness. Second, we show that when choice functions are strongly OS, weak group strategy-proofness of the COM reduces to individual strategy-proofness. However, strong OS is neither necessary nor "almost necessary" for this reduction.
Comments43 pages, 1 figure, 2 tables
