Kensuke Suzuki | Searcharxiv

arXiv2025

Trade Policy and Structural Change

We study how tariffs affect industrial structure and welfare in an economy where sectors are complements and preferences are nonhomothetic---two drivers of structural change. Tariffs reshape sectoral composition through relative prices, income effects, and sectoral net exports. We characterize these mechanisms analytically and quantify them in a dynamic multi-country model with capital accumulation and input-output linkages. A counterfactual 20-percentage-point increase in U.S. manufacturing tariffs raises the manufacturing value-added share by about one percentage point and increases U.S. welfare by 0.43 percent, while lowering welfare abroad; retaliation would make all countries worse off. The optimal unilateral U.S. manufacturing tariff is 20.9 percent. Comparing different preference specifications, we show that homothetic preferences without income effects overstate the U.S. welfare gains from unilateral tariff increases.

econ.GN↗

arXiv2016

Near-Infrared Spectroscopy of Faint Discrete X-ray Point Sources Constituting the Galactic Ridge X-ray Emission

The Galactic Ridge X-ray Emission (GRXE) is apparently extended X-ray emission along the Galactic Plane. The X-ray spectrum is characterized by hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (~80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations, thus GRXE is mostly composed of dim Galactic X-ray point sources at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out Near-Infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l,b)=(0.1{\arcdeg}, -1.4{\arcdeg}) and (28.5{\arcdeg}, 0.0{\arcdeg}) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as HI(Brγ), HeI, and HeII (2 objects), (B) soft X-ray spectra and NIR absorption features such as HI, NaI, CaI, and CO (46 objects), and (C) hard X-ray spectra and NIR absorption features such as HI, NaI, CaI and CO (17 objects). From these features, we argue that class A sources are Cataclysmic Variables (CVs), and class B sources are late-type stars with enhanced coronal activity, which is in agreement with current knowledge. Class C sources possibly belong to a new group of objects, which has been poorly studied so far. We argue that the candidate sources for class C are the binary systems hosting white dwarfs and late-type companions with very low accretion rates. It is likely that this newly recognized class of the sources contribute to a non-negligible fraction of the GRXE, especially in the Fe K band.

astro-ph.HE↗

arXiv2010

Change of the Ground State upon Hole Doping Unveiled by Ni Impurity in High-$T_{\rm c}$ Cuprates

The electronic ground state in high-$T_{\rm c}$ cuprates where the superconducting state is suppressed by Ni substitution has been investigated in La$_{2-x}$Sr$_x$Cu$_{1-y}$Ni$_y$O$_4$ from the specific heat and muon spin relaxation measurements. It has been found that the ground state changes from a magnetically ordered state with the strong hole-trapping by Ni to a metallic state with the Kondo effect of Ni with increasing hole-concentration. Moreover, the analysis of the results has revealed that a phase separation into the magnetically ordered phase and the metallic phase occurs around the boundary of two phases.

cond-mat.supr-con↗