We consider the problem of allocating heterogeneous and indivisible goods among strategic agents, with preferences over subsets of goods, when there is no medium of exchange. This model captures the well studied problem of fair allocation of indivisible goods. Serial-quota mechanisms are allocation mechanisms where there is a predefined order over agents, and each agent in her turn picks a predefined number of goods from the remaining goods. These mechanisms are clearly strategy-proof, non-bossy, and neutral. Are there other mechanisms with these properties? We show that for important classes of strict ordinal preferences (as lexicographic preferences, and as the class of all strict preferences), these are the only mechanisms with these properties. Importantly, unlike previous work, we can prove the claim even for mechanisms that are not Pareto-efficient. Moreover, we generalize these results to preferences that are cardinal, including any valuation class that contains additive valuations. We then derive strong negative implications of this result on truthful mechanisms for fair allocation of indivisible goods to agents with additive valuations.

翻译：我们考虑在无交换媒介的情况下，将异质且不可分割的物品分配给策略性智能体的问题，其中智能体对物品子集具有偏好。该模型涵盖了经过充分研究的不可分割物品公平分配问题。序列配额机制是一类分配机制，其中智能体之间存在预定义的顺序，每位智能体依次从剩余物品中挑选预定义数量的物品。这些机制显然满足策略证明性、非专断性和中立性。是否存在其他具备这些性质的机制？我们证明，对于重要的严格序数偏好类别（如词典序偏好和所有严格偏好类别），这些性质所对应的机制仅此一例。重要的是，与先前工作不同，我们甚至能为非帕累托效率的机制证明该论断。此外，我们将这些结果推广至基数偏好（包括包含加性估值的任意估值类别）。基于此，我们推导出该结果对具有加性估值的智能体进行不可分割物品公平分配时诚实机制的强负面含义。