We study the existence and properties of social choice functions when each individual’s preference order is incomplete: each individual expresses his/her preference on his/her alternative set that is a subset of the whole set of alternatives. We define the strategy-proofness and show that the strategy-proofness is incompatible with nondictatorship. In addition, we weaken the definition of the s...

Several conceptual points are made concerning communication in games of asymmetric information. Equilibrium refinements of Sender-Receiver cheap-talk games that are based on the concept of a putative equilibrium, and which rely on the presence of a rich language with literal meanings, are discussed. Three nested criteria are proposed: strong announcement-proofness, announcement-proofness, and w...

Recently there are several works which analyzed the strategy−proofness of non−resolute social choice rules such as Duggan and Schwartz (2000) and Ching and Zhou (2001). In these analyses it was assumed that individual preferences are linear, that is, they excluded indifference from individual preferences. We present an analysis of the strategy−proofness of non−resolute social choice rules when ...

We study the problem of assigning indivisible and heterogenous objects (e.g., houses, jobs, offices, school or university admissions etc.) to agents. Each agent receives at most one object and monetary compensations are not possible. We consider mechanisms satisfying a set of basic properties (unavailable-type-invariance, individual-rationality, weak non-wastefulness, or truncation-invariance)....

Strategy‐proofness (SP) is a sought‐after property in social choice functions because it ensures that agents have no incentive to misrepresent their private information at both the interim and ex post stages. Group strategy‐proofness (GSP), however, notion applied stage but not stage. Thus, we propose new of GSP, coined robust group (RGSP), which benefits by deviating from truth telling We show...

Strategy-proof implementation is one of the many elements that have contributed to the successful application of matching theory in real life. However, in many-to-one matching markets without transfers (e.g., doctors to hospitals with fixed salaries) there is no stable mechanism which is strategy-proof for hospitals. Furthermore, strategy-proofness and stability cannot be achieved for both hosp...

There are many concepts of nonmanipulability, including strategy-proofness (and its several coalitional variants), Nash implementability, self Nash implementability, and nonbossi-ness. We explore the relationships between these concepts in the context of continuous social choice functions (SCF's). For any continuous SCF on a continuously and monotonically closed domain, we nd that strategy-proo...

In the context of a simple model of public good provision, we study the requirement on an allocation rule that it be immune to manipulation by augmenting one’s endowment through borrowing from the outside world. We call it open-economy borrowing-proofness (Thomson, 2009). We ask whether the Lindahl rule satisfies the property. The answer is yes on both the domain of quasi-linear economies and o...