Zombie Firms and Economic Stagnation in Japan

It is often claimed that one contributing factor to Japan's weak economic performance over the past decade is that Japanese banks have continued to provide financial support for highly inefficient, debt-ridden companies, commonly referred to as "zombie" firms. Such poor banking practices in turn prevent more productive companies from gaining market share, strangling a potentially important source of productivity gains for the overall economy. To explore further the zombie-firm hypothesis, we use industry- and firm-level Japanese data and find evidence that productivity growth is low in industries reputed to have heavy concentrations of zombie firms. We also find that the reallocation of market share is going in the wrong direction in these industries, adding to already weak productivity performance. In addition, we find evidence that financial support from Japanese banks may have played a role in sustaining this perverse reallocation of market share.Productivity, banking system, creative destruction

Gender Inclusion in Climate Change Adaptation

There is increasing evidence that climate change has an impact on natural disasters, such as flooding, and on agricultural production, both of which have implications for gender issues. In this paper the authors briefly review issues related to gender and poverty and examine the relationships between gender and various indices. They then look at systems of land ownership and inheritance, and discuss an example of job recovery after a disaster through interviews with three female agricultural workers in Japan. The results of the interviews demonstrate the recent empowerment of women in agricultural production and that these women have strong adaptive abilities.climate change; natural disasters; gender issues; agricultural production

Monetary Policy and Transmission of Bubbles

The aim of this paper is to investigate the optimal monetary policy when bubbles boost and burst. The monetary policy in the form of open market operation has real effects, that is, influences the growth in investment and the size of bubbles. The central bank faces a trade-off between stimulating investment and appreciating bubbles. The optimal policy is contingent on the state of bubbles. When bubbles arise, the central bank may maintain or gives up easing, depending on how it puts weight on the state of the bursting of bubbles, while when bubbles burst, the central bank takes an easing policy. The optimal policy is the same irrespective of whether foreign capital inflows are allowed for unless capital markets are severely restricted

フセイ ユウシ ニ タイスル ケイジ セキニン

末永敏和教授退職記念

フジツ ノ テイトウケン セッテイ カリトウキ ト オウリョウザイ サイケツ ヘイセイ ニジュウイチネン サンガツ ニジュウロクニチ ケイシュウ ロクジュウサンカン サンゴウ ニヒャクキュウジュウイチコウ

判例研

ハイニンザイ ニ オケル ザイサンジョウ ノ ソンガイ ヨウケン ニ ツイテ 1

論

Excitons in boron nitride nanotubes: dimensionality effects

We show that the optical absorption spectra of boron nitride (BN) nanotubes are dominated by strongly bound excitons. Our first-principles calculations indicate that the binding energy for the first and dominant excitonic peak depends sensitively on the dimensionality of the system, varying from 0.7 eV in bulk hexagonal BN via 2.1 eV in the single sheet of BN to more than 3 eV in the hypothetical (2,2) tube. The strongly localized nature of this exciton dictates the fast convergence of its binding energy with increasing tube diameter towards the sheet value. The absolute position of the first excitonic peak is almost independent of the tube radius and system dimensionality. This provides an explanation for the observed "optical gap" constancy for different tubes and bulk hBN [R. Arenal et al., to appear in Phys. Rev. Lett. (2005)].Comment: 5 pages, 2 figure

Single ion implantation for single donor devices using Geiger mode detectors

Electronic devices that are designed to use the properties of single atoms such as donors or defects have become a reality with recent demonstrations of donor spectroscopy, single photon emission sources, and magnetic imaging using defect centers in diamond. Improving single ion detector sensitivity is linked to improving control over the straggle of the ion as well as providing more flexibility in lay-out integration with the active region of the single donor device construction zone by allowing ion sensing at potentially greater distances. Using a remotely located passively gated single ion Geiger mode avalanche diode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of >75 um from the center of the collecting junction. This detection efficiency is achieved with sensitivity to ~600 or fewer electron-hole pairs produced by the implanted ion. Ion detectors with this sensitivity and integrated with a thin dielectric, for example 5 nm gate oxide, using low energy Sb implantation would have an end of range straggle of <2.5 nm. Significant reduction in false count probability is achieved by modifying the ion beam set-up to allow for cryogenic operation of the SIGMA detector. Using a detection window of 230 ns at 1 Hz, the probability of a false count was measured as 1E-1 and 1E-4 for operation temperatures of 300K and 77K, respectively. Low temperature operation and reduced false, dark, counts are critical to achieving high confidence in single ion arrival. For the device performance in this work, the confidence is calculated as a probability of >98% for counting one and only one ion for a false count probability of 1E-4 at an average ion number per gated window of 0.015.Comment: 10 pages, 5 figures, submitted to Nanotechnolog

Transmission of PM-QPSK and PS-QPSK with different fiber span lengths

We perform experimental and numerical investigations of the transmission reach of polarization-switched QPSK (PS-QPSK) and polarization-multiplexed QPSK (PM-QPSK) for three different fiber span lengths: 83, 111 and 136 km. In the experimental comparison we investigate the performance of PS-QPSK at 20 Gbaud and PM-QPSK at the same bit rate (60 Gbit/s) and at the same symbol rate, both the single channel case and a WDM system with 9 channels on a 50 GHz grid. We show that PS-QPSK gives significant benefits in transmission reach for all span lengths. Compared to PM-QPSK, use of PS-QPSK increases the reach with more than 41 % for the same symbol rate and 21 % for the same bit rate. In the numerical simulations we use the same data rates as in the experiment. The simulation results agree well with the experimental findings, but the transmission reach is longer due to the absence of various non-ideal effects and higher back-to-back sensitivity. Apart from using data coded in the absolute phase in the simulations, we also investigate differentially coded PS-QPSK for the first time and compare with PM-QPSK with differential coding. The power efficiency advantage of PS-QPSK then increases with approximately 0.3 dB at a bit error rate of 10-3, resulting in a further relative transmission reach improvement over PM-QPSK. Both the experimental and the numerical results indicate that PS-QPSK has slightly higher tolerance to inter-channel nonlinear crosstalk than PM-QPSK