In this paper, we show that in pure exchange economies where the number of goods equals or exceeds the number of agents, any Pareto-efficient and strategy-proof allocation mechanism always allocates the total endowment to some single agent even if the receivers vary.

We consider the problem of allocating a single object to the agents with payments. Agents have preferences that are not necessarily quasi-linear. We characterize the class of rules satisfying pairwise strategy-proofness and non-imposition by the priority rule. Our characterization result remains...