The classical theory of efficient allocations of an aggregate endowment in a pure-exchange economy has hitherto primarily focused on the Pareto-efficiency of allocations, under the implicit assumption that transfers between agents are frictionless, and hence costless to the economy. In this paper, we argue that certain transfers cause frictions that result in costs to the economy. We show that these frictional costs are tantamount to a form of subadditivity of the cost of transferring endowments between agents. We suggest an axiomatic study of allocation mechanisms, that is, the mechanisms that transform feasible allocations into other feasible allocations, in the presence of such transfer costs. Among other results, we provide an axiomatic characterization of those allocation mechanisms that admit representations as robust (worst-case) linear allocation mechanisms, as well as those mechanisms that admit representations as worst-case conditional expectations. We call the latter Robust Conditional Mean Allocation mechanisms, and we relate our results to the literature on (decentralized) risk sharing within a pool of agents.

翻译：经典理论在纯交换经济中对总禀赋的有效配置研究，迄今主要聚焦于配置的帕累托效率，其隐含假设是代理人之间的转移无摩擦，因而对经济无成本。本文认为，某些转移会引发摩擦，导致经济成本。我们证明这些摩擦成本等价于代理人之间禀赋转移成本的一种次可加性形式。我们提出在此类转移成本存在的情况下，对分配机制——即将可行配置转化为其他可行配置的机制——进行公理化研究。除其他结果外，我们公理化刻画了那些可表示为鲁棒（最坏情况）线性分配机制的机制，以及那些可表示为最坏情况条件期望的机制。我们将后者称为鲁棒条件均值分配机制，并将我们的结果与（去中心化）代理人池内风险分担的相关文献联系起来。