A Note on Aumann's Core Equivalence Theorem without Monotonicity

In an exchange economy with a continuum of traders, we establish the equivalence theorem on the core and the set of competitive allocations without assuming monotonicity of traders' preferences. Under weak assumptions we provide two alternative core equivalence theorems. The first one is for irreducible economies under Debreu's assumption on quasi-equilibria. The second one is an extension of Aumann's theorem under weaker assumptions than monotonicity.core, equivalence, monotonicity, quasi-equilibrium, irreducibility

Games with the Total Bandwagon Property

We consider the class of two-player symmetric n x n games with the total bandwagon property (TBP) introduced by Kandori and Rob (1998). We show that a game has TBP if and only if the game has 2^n - 1 symmetric Nash equilibria. We extend this result to bimatrix games by introducing the generalized TBP. This sheds light on the (wrong) conjecture of Quint and Shubik (1997) that any n x n bimatrix game has at most 2^n - 1 Nash equilibria. As for an equilibrium selection criterion, I show the existence of a ½-dominant equilibrium for two subclasses of games with TBP: (i) supermodular games; (ii) potential games. As an application, we consider the minimum-effort game, which does not satisfy TBP, but is a limit case of TBP. (author's abstract)Series: Department of Economics Working Paper Serie

Intermediary Search for Suppliers in Procurement Auctions

In many procurement auctions, entrants determine whether to participate in auctions accounting for their roles of intermediaries who search for the best (or the cheapest) input suppliers. We build on a procurement auction model with entry, combining with intermediary search for suppliers. The novel feature is that costs of bidders are endogenously determined by suppliers who strategically charge input prices. We show the existence of an equilibrium with price dispersion for inputs, generating cost heterogeneity among bidders. Interestingly, the procurement cost may rise as the number of potential bidders increases. (author's abstract)Series: Department of Economics Working Paper Serie

Open-architecture Implementation of Fragment Molecular Orbital Method for Peta-scale Computing

We present our perspective and goals on highperformance computing for nanoscience in accordance with the global trend toward "peta-scale computing." After reviewing our results obtained through the grid-enabled version of the fragment molecular orbital method (FMO) on the grid testbed by the Japanese Grid Project, National Research Grid Initiative (NAREGI), we show that FMO is one of the best candidates for peta-scale applications by predicting its effective performance in peta-scale computers. Finally, we introduce our new project constructing a peta-scale application in an open-architecture implementation of FMO in order to realize both goals of highperformance in peta-scale computers and extendibility to multiphysics simulations.Comment: 6 pages, 9 figures, proceedings of the 2nd IEEE/ACM international workshop on high performance computing for nano-science and technology (HPCNano06