It is proved that, among all restricted preference domains that guarantee consistency (i.e. transitivity) of pairwise majority voting, the single-peaked domain is the only minimally rich and connected domain that contains two completely reversed strict preference orders. It is argued that this...

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 problems of fairly allocating indivisible objects and money. The objective of the present study is to examine strategic manipulation under envy-free solutions. We show that each individual obtains the welfare level of his "optimal" envy-free allocation by maximally manipulating...

In this paper, virtual implementation is restricted so that only a socially optimal outcome or some fixed outcome (a status quo) can be delivered on the equilibrium path. Under such a restriction, any unanimous and implementable social choice function is almost-dictatorial. That is, there is an...

We consider a relational economy in which economic agents participate in three types of relational economic activities: autarkic activities; binary matching activities; and plural cooperative activities. We introduce a stability notion and characterize stable interaction structures, both in the...

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 extend approval voting so as to elect multiple candidates, who may be either individuals or members of a political party, in rough proportion to their approval in the electorate. We analyze two divisor methods of apportionment, first proposed by Jefferson and Webster, that iteratively...

This paper studies the possibility of secure implementation (Saijo, T., T. Sjöström, and T. Yamato (2007) "Secure Implementation," Theoretical Economics 2, pp. 203-229) in divisible and non-excludable public good economies with quasi-linear utility functions. Although Saijo, Sjöström, and...

In this paper we deal with situations of collective contests between two groups over a private prize. A well known way to divide the prize within the winning group is the prize sharing rule introduced by Nitzan, 1991. Since its introduction it has become a standard in the collective contests...

This paper analyzes strategy-proof collective choice rules when individuals have single-crossing preferences on a finite and ordered set of social alternatives. It shows that a social choice rule is anonymous, unanimous, and strategy-proof on a maximal single-crossing domain if and only if it is...