"Search under the Knightian Uncertainty"

Suppose that "uncertainty" about labor market conditions has increased. Does this change induce an unemployed worker to search longer, or shorter? This paper shows that the answer is drastically different depending on whether an increase in "uncertainty" is an increase in risk or that in true uncertainty in the sense of Frank Knight. We show in a general framework that, while an increase in risk (the mean-preserving spread of the wage distribution that the worker thinks she faces) increases the reservation wage, an increase in the Knightian uncertainty (a decrease in her confidence about the wage distribution) reduces it.

"Economics of Self-Feeding Fear"

A model of self-feeding fear is presented. Suppose that an economic agent is (1-ƒÃ)~100% certain that uncertainty she faces is characterized by a particular probability measure, but that she has a fear that, with ƒÃ~100% chance, her conviction is completely wrong and she is left perfectly ignorant about the true measure in the present as well as in the future. We call this situation ƒÃ-contamination of confidence. In this situation, if the economic agent follows Bayesian procedure or its variant, which is considered as rational in the theory of economics, her confidence erodes after having new observation.

Feasibility of a storage ring for polar molecules in strong-field-seeking states

We show, through modeling and simulation, that it is feasible to construct a storage ring that will store dense bunches of strong-field-seeking polar molecules at 30 m/s (kinetic energy of 2K) and hold them, for several minutes, against losses due to defocusing, oscillations, and diffusion. The ring, 3 m in diameter, has straight sections that afford access to the stored molecules and a lattice structure that may be adapted for evaporative cooling. Simulation is done using a newly-developed code that tracks the particles, in time, through 400 turns; it accounts for longitudinal velocity changes as a function of external electric field, focusing and deflection nonlinearities, and the effects of gravity. An injector, decelerator, and source are included and intensities are calculated.Comment: 6 pages 5 figures, 3 table

"A Simple Axiomatization of Iterated Choquet Objectives"

A set of axioms which characterizes a preference representable by the iterated Choquet expected utility is presented. This objective function is attractive since it possesses a feature of dynamical consistency. Furthermore,we show that under the same axioms the conditional preference is represented by the Choquet expected utility with respect to the capacity which is updated according to the Dempster-Shafer rule. We do this by weakening Schmeidler's axiom of comonotonic independence to our axiom of constrained comonotonic independence and by adding the axiom of dynamical consistency.

"Distortion in Land Price Information---Mechanism in Sales Comparables and Appraisal Value Relation---"

This paper investigates the nature and magnitude of distortion in land price information publicly available in Japan, especially in the Published Land Price of the Japanese Government. After examining characteristics of various land price information in Japan, we construct hedonic price indexes based on both actual transaction prices and Published Land Prices, and compare them to find possible distortion in the governmental price information. We find a large and systematic discrepancy between actual transaction prices and Published Land Prices, suggesting serious problems in the governmental information system. We also consider possibility of structural change in the Japanese real estate markets, and examine its effect on price indexes.

Spontaneous Breakdown of Lorentz Invariance in IIB Matrix Model

We study the IIB matrix model, which is conjectured to be a nonperturbative definition of superstring theory, by introducing an integer deformation parameter `nu' which couples to the imaginary part of the effective action induced by fermions. The deformed IIB matrix model continues to be well-defined for arbitrary `nu', and it preserves gauge invariance, Lorentz invariance, and the cluster property. We study the model at `nu' = infinity using a saddle-point analysis, and show that ten-dimensional Lorentz invariance is spontaneously broken at least down to an eight-dimensional one. We argue that it is likely that the remaining eight-dimensional Lorentz invariance is further broken, which can be checked by integrating over the saddle-point configurations using standard Monte Carlo simulation.Comment: 12 pages, latex, no figures, references added, version to appear in JHE

"Innovation Versus Diffusion: Determinants of Productivity Growth Among Japanese Firms"

This paper presents a model of firm-level productivity growth that distinguishes between innovation and technology diffusion, and then applies the model to a large-scale data set of Japanese manufacturing and non-manufacturing firms between 1994 and 2000. We find both innovation and diffusion are important factors in firm-level productivity growth. Results also suggest that innovation comes not only directly from R&D activities, but also indirectly from patent purchases and imports. Previously, patent purchases and imports were considered as sources of technology diffusion rather than innovation. In fact, we find patent purchases are more effective in this regard than R&D expenditure.

"Measuring the Cost of Imperfect Information in the Tokyo Housing Market"

The cost of imperfect information is estimated in the real estate market of resale condominiums in central Tokyo by using a new, comprehensive data set of resale condominium transactions. The results suggest a substantial cost. Specifically, if information were perfectly available and marketing time is null, sellers would get benefits of 10.58% based on average interest rate, 31.28% on gross rent and 22.59% on net rent, against imputed rent of their property. Buyers spend 1,042,000 Yen on search activities for one transaction, which would be saved if information were prefect. This cost amounts to be equivalent to 13.2% of buyers' average annual income.

"Productivity Convergence at the Firm Level"

Productivity convergence among countries has been investigated extensively with mixed results. This paper extends the analysis to the firm level to shed light on the debate of convergence or non-convergence. We find productivity convergence among firms widely in Japan, in both manufacturing industries and non-manufacturing ones. We obtain these results taking explicit account of exiting firms as a source of selection biases. The convergence rate is much faster among firms than countries. We also find that there are substantial differences among industries in the convergence speed. IT industries that heavily rely on technological progress show faster rates of convergence.