Following Barberà, Sonnenschein, and Zhou (1991, Econometrica 59, 595-609), we study rules (or social choice functions) through which agents select a subset from a set of objects. We investigate domains on which there exist nontrivial strategy-proof rules. We establish that the set of separable...

This paper studies the possibility of strategy-proof rules yielding satisfactory solutions to matching problems. Alcalde and Barberá (1994) show that effcient and individually rational matching rules are manipulable in the one-to-one matching model. We pursue the possibility of strategy-proof...

This paper studies the application of the notion of secure implementation (Cason, Saijo, Sjöström, and Yamato, 2006; Saijo, Sjöström, and Yamato, 2007) to the problem of allocating indivisible objects with monetary transfers. We propose a new domain-richness condition, termed as minimal...

We study dominant strategy implementation especially in economic environments. We first showthat in general environments, strategy-proofness and quasi-strong-non-bossiness together are necessary and sufficient for dominant strategy implementation via the associated direct revelationmechanism. We...

We consider the problem of allocating infinitely divisible commodities among a group of agents. Especially, we focus on the case where there are several commodities to be allocated, and agents have continuous, strictly convex, and separable preferences. In this paper, we establish that the...

We confront two common objections to Harsanyi's impartial observer theorem; one to do with 'fairness', and the other to do with different individuals' having different attitudes toward risk. Both these objections can be accommodated if we drop the reduction axiom; in particular, if we...

It is known that on some social choice and economic domains, a social choice function is coalition strategy-proof if and only if it is Maskin monotonic (e.g. Muller and Satterthwaite, 1977). This paper studies the foundation of those results. I provide a set of conditions which is sufficient for...

We consider the allotment problems of homogeneous indivisible objects among agents with single-peaked and risk-averse von Neumann-Morgenstern expected utility functions. We establish that the rule satisfies coalitional strategy-proofness, same-sideness, and strong symmetry if and only if it is...

This paper considers the object allocation problem introduced by Shapley and Scarf (1974). We study secure implementation (Saijo, Sjöström, and Yamato, 2007), that is, double implementation in dominant strategy and Nash equilibria. We prove that (i) an individually rational solution is...

This paper examines the questions of who participates in the provision of a public good through the voluntary participation of agents in the presence of strong complementarity between a public good and a private good. We show that the greater the initial endowment of the private good that agents...