Alternate contracts for side payments

We characterize efficient equilibrium outcomes of two-player games that remain equilibrium outcomes even when the two players may alternately make binding offers of strategy contingent side payments before the game is played. Our characterization result implies that alternately contracting for side payments has more efficiency of a certain type in equilibria than simultaneously side contracting which is analyzed by Jackson and Wilkie (2005).alternate contracts

Efficient equilibrium side contracts

We analyze two-stage games where players may make binding offers of schemes for side payment acceptance (or rejection) as well as those for side payments before choosing actions. We find that any set of efficient actions maximizing the total payoff is played on an equilibrium path of the two-stage game when such bilateral contracts on side payments are interdependent.

Triple implementation by sharing mechanisms in production economics with unequal labor skill

labor sovereignty, triple implementation, different labor skills

Nash Implementation in Production Economies with Unequal Skills: A Complete Characterization

In production economies with unequal labor skills, where the planner is ignorant to the set of feasible allocations in advance of production, the paper firstly introduces a new axiom, Nonmanipulability of Irrelevant Skills (NIS), which together with Maskin Monotonicity constitute the necessary and sufficient conditions for Nash implementation. Secondly, the paper defines natural mechanisms, and then fully characterizes Nash implementation by natural mechanisms, using a slightly stronger variation of NIS and Supporting Price Independence. Following these characterizations, it is shown that there is a Maskin monotonic allocation rule which is not implementable when information about individual skills is absent. In contrast, many fair allocation rules, which are known to be non-implementable in the present literature, are implementable by the natural mechanisms.Unequal labor skills, Nash implementation, Nonmanipulability of Irrelevant Skills

Nash Implementation in Production Economies with Unequal Skills : A Complete Characterization

In production economies with unequal labor skills, one of the intrinsic features for Nash implementation problems is the lack of information about individual skills, which makes the planner ignorant to the set of feasible allocations in advance of production. Given this intrinsic feature, the paper firstly introduces a new axiom, Non-manipulability of Irrelevant Skills (NIS), which together with Maskin Monotonicity constitute the necessary and sufficient conditions for Nash implementation. Secondly, the paper defines some conditions for natural mechanisms which seem relevant, and then shows that any efficient allocation rule is Nashimplementable by the natural mechanisms if and only if it satisfies a slightly stronger variation of NIS and Supporting Price Independence. Following these characterizations, it is shown that there is a Maskin monotonic allocation rule which is not implementable when information about individual skills is absent. In contrast, there are many fair allocation rules which are known to be non-implementable in the present literature, but are implementable by the natural mechanisms given in this paper.Unequal labor skills, Nash implementation, Nonmanipulability of Irrelevant Skills

Quantitative Evaluation of Liver Function within MR Imaging

Quantitative evaluation of liver function is important not only for monitoring of that function, but also for preoperative assessment of the liver reserve. Recent advances and future view in quantitative evaluation of liver function within MR imaging was described.ArticleOMICS Journal of Radiology. 1:e109 (2012)journal articl

Hydrodynamical effects in internal shock of relativistic outflows

We study both analytically and numerically hydrodynamical effects of two colliding shells, the simplified models of the internal shock in various relativistic outflows such as gamma-ray bursts and blazars. We pay particular attention to three interesting cases: a pair of shells with the same rest mass density (``{\it equal rest mass density}''), a pair of shells with the same rest mass (``{\it equal mass}''), and a pair of shells with the same bulk kinetic energy (``{\it equal energy}'') measured in the intersteller medium (ISM) frame. We find that the density profiles are significantly affected by the propagation of rarefaction waves. A split-feature appears at the contact discontinuity of two shells for the ``equal mass'' case, while no significant split appears for the ``equal energy'' and ``equal rest mass density'' cases. The shell spreading with a few ten percent of the speed of light is also shown as a notable aspect caused by rarefaction waves. The conversion efficiency of the bulk kinetic energy to internal one is numerically evaluated. The time evolutions of the efficiency show deviations from the widely-used inellastic two-point-mass-collision model.Comment: 29 pages, 16 figures, accepted by Ap