"Demand for non-life insurance: A cross-country analysis"

A number of existing studies on insurance demand report an apparently pathological result that insurance is a luxury good. Using cross-country insurance data and national wealth data, we resolve this spurious puzzle. While we found that the income elasticity of insurance demand is larger than unity, the wealth elasticity of insurance demand is smaller than unity at least for upper-middle and high wealth countries.

Discovery of Enhanced Radiative Recombination Continua of He-like Iron and Calcium from IC 443 and Its Implications

We present deep observations of the Galactic supernova remnant IC 443 with the {\it Suzaku X-ray satellite}. We find prominent K-shell lines from iron and nickel, together with a triangle residual at 8--10~keV, which corresponds to the energy of the radiative recombination continuum (RRC) of He-like iron. In addition, the wavy residuals have been seen at $\sim$5.1 and $\sim$5.5~keV. We confirm that the residuals show the first enhanced RRCs of He- and H-like calcium found in supernova remnants. These facts provide robust evidence for the recombining plasma. We reproduce the plasma in the 3.7--10~keV band using a recombining plasma model at the electron temperature 0.65~keV. The recombination parameter $n_{\rm e}t$ ($n_{\rm e}$ is electron density and $t$ is elapsed time after formation of a recombining plasma) and abundances of iron and nickel are strongly correlated, and hence the errors are large. On the other hand, the ratio of nickel to iron relative to the solar abundances is well constrained to 11$^{+4}_{-3}$ (1$\sigma$). A possibility is that the large abundance ratio is a result of an asymmetric explosion of the progenitor star.Comment: 4 pages, 5 figures, published in Ap

The Effect of Bank Recapitalization Policy on Credit Allocation, Investment, and Productivity: Evidence from a Banking Crisis in Japan

departmental bulletin pape

確率共鳴理論を応用した腹腔鏡下手術における触覚向上の取り組み

内容の要旨 , 審査の要旨広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

Self-Production, Friction, and Risk Sharing against Disasters: Evidence from a developing country

This paper uses a unique household data set collected in Vietnam to empirically test the necessary conditions for an extended version of the consumption risk-sharing hypothesis. The test explicitly incorporates self-production and uses natural disasters such as avian influenza, droughts, and floods to identify the effectiveness of market and non-market risk-sharing mechanisms. With these additional treatments, full risk sharing cannot be rejected, which suggests the presence of omitted variable bias in existing studies that reject full risk sharing. We also find that credit constraints have a significant impact, although limited commitment is not necessarily serious.

Entropy Characterisation of Insurance Demand: Theory and Evidence

This paper characterises the insurance demand in terms of the entropy of the underlying probability distribution for losses. A characterisation of this nature provides the prediction that insurance for large losses with small probabilities tends to be purchased less frequently than insurance for moderate losses with higher probabilities, without deviating from the standard expected utility framework. The predictions of the theoretical model are tested empirically using household data collected in Vietnam.

Is Aid Allocation Consistent with Global Poverty Reduction?: A Cross-Donor Comparison

In this paper, we investigate the gap between the first target of the Millennium Development Goals (MDGs) and the actual allocation of grant aid in the late-1990s and the early-2000s in order to identify necessary policy adjustments to achieve the goal. As a theoretical framework, we extend the poverty-targeting model of Besley and Kanbur (1988) by considering multiple donors and possible strategic interactions among them. To test theoretical predictions, we employ detailed data on grant aid allocation of eleven major aid donor countries and on aid disbursement of six international institutions including the IBRD, IDA, and UN organizations. Four main empirical results emerged. First, both in the late-1990s and the early-2000s, grant allocations from Canada, France, Japan, the Netherlands, and UK are consistent with the necessary conditions of optimal poverty targeting. Second, we found that there is a negative population scale effect for aid allocation, suggesting that strategic motives may also exist. Third, the overall results for multilateral donors indicate that allocation patterns are consistent with the theory of poverty targeting. Finally, there has been a recent improvement in coordination among major donors in reducing global poverty.

Asking Retrospective Questions in Household Surveys: Evidence from Vietnam

Asking retrospective questions about consumption and income has become an important part of household surveys and research in developing countries. While recall errors in retrospective data may generate estimation biases, the nature and the magnitude of the errors are largely unknown, especially in the context of developing countries. To fill this gap in the existing studies, we collect unique household data from Vietnam, a resurvey of respondents of the Vietnam Health and Living Standard Survey (VHLSS) 2006. This combined data allows us to investigate a variety of errors associated with recall surveys and the size of consumption categories in questionnaires. Our empirical results suggest that asking for total expenditure, rather than categorical expenditure, will cause fewer recall errors in a retrospective survey. This is especially true in the case of purchased or bartered consumption expenditure. Our results also suggest that while recall errors in the categorical sum of expenditure may exhibit mean-reverting patterns, retrospective total expenditure data is less likely to involve problems of mean reverting measurement error.

Metamaterials with magnetism and chirality

This review introduces and overviews electromagnetism in structured metamaterials which undergo simultaneous time-reversal and space-inversion symmetry breaking due to magnetism and chirality. Direct experimental observation of optical magnetochiral effects in a single metamolecule with magnetism and chirality is demonstrated at microwave frequencies. Numerical simulations based on a finite element method reproduce the experimental results well, and predict the emergence of giant magnetochiral effects, by combining resonances in the metamolecule. Toward the realization of magnetochiral effects at higher frequencies than microwaves, a metamolecule is miniaturized in the presence of ferromagnetic resonance in a cavity and coplanar waveguide. This work opens the door to the realization of a one-way mirror and synthetic gauge fields for electromagnetic waves