Rationality on Final Decisions Leads to Sequential Equilibrium

The purpose of this article is to investigate epistemic conditions for a sequential equilibrium in an extensive form game with imperfect information: If players mutually know that all players maximize their own expected payoffs at any information sets in their final decisions then their behaviors with belief yield a sequential equilibrium. This result is an extension of Aumann (1995, Games and Economic Behavior, 8:6-19) in a perfect information game. In this article, we propose the nation of 'mu'-rationality, by which we mean that player knows that he maximizes his own payoff according to the common-belief 'mu'. Our main theorem states that mutual knowledge of both 'mu'-rationality and 'mu'-consistency induces a sequential equilibrium outcome in an extensive form game.Knowledge, Rationality, Epistemic conditions, Backward induction, Sequential equilibrium

Core Equivalence in Economy under Generalized Information

We investigate a pure exchange atomless economy under uncertainty with emphasis on an epistemic point of view, where the traders are assumed to have a non-partitional information structure. We propose a generalized notion of rational expectations equilibrium for the economy and we show the core equivalence theorem: The ex-post core for the economy coincides with the set of all its rational expectations equilibria.Pure exchange economy under refexive information structure, Ex-post core, Rational expectations equilibrium, Core equivalence theorem

No Speculation in Rational Expectations under Generalized Information

Let us consider a pure exchange economy under non-partitional information where the traders are assumed to have a reflexive and transitive information structure and to have strictly monotone preferences. We show the no speculation theorem: If the initial endowment is ex-ante Pareto optimal then there exists no other rational expectations equilibrium for any price with respect to which all traders are rational about expectations everywhere.Pure exchange economy with knowledge, No speculation, Rational expectations equilibrium, Ex-ante Pareto optimum

An extrusion method of tube with spiral inner fins by utilizing generation of spiral outer fins/grooves

This paper presents a new extrusion method for fabrication of a tube with spiral inner fins. The spiral fins are formed by utilizing the generation of spiral outer fins or grooves, which drive the metal to circumferentially move with twist deformation. The effect of the outer fins/grooves is examined for realizing the circumferential metal flow. The position of the mandrel has an ability to flexibly control the spiral angle. This method would drastically enhance the productivity and reduce the manufacturing cost, as the tube would be manufactured directly from a billet through only one process