26,367 research outputs found

    Testing for a time-varying price-cost markup in the Euro area inflation process

    Get PDF
    Empirical models of inflation often incorporate equilibrium correction effects based upon levels of prices and input costs. Such models assume that the steady-state price-cost markup is constant, but recent research suggests that this may not be true for the Euro area economy, which has undergone major structural reforms over the last 25 years. We allow for permanent shifts in the markup factor through estimating an inflation equation that includes a time-varying intercept. The model suggests that a reduction in the markup contributed to disinflation in the Euro area during the period 1981-2000.inflation;price-cost markup;cointegration;time-varying intercept;dynamic modelling.

    A markup model of inflation for the euro area

    Get PDF
    Equilibrium correction models of the price level are often used to model inflation. Such models assume that the long-run markup of prices over costs is fixed, but this may not be true for the Euro area economy, which has undergone major structural reforms over the last 25 years. We allow for shifts in the markup factor through estimating an equation that includes a timevarying intercept. The model fits the data better than a linear alternative, and suggests that a reduction in the price-cost markup contributed to disinflation in the Euro area during the 1980s. JEL Classification: C22,C32,E31cointegration, dynamic modelling, inflation, price-cost markup, time-varying intercept

    Testing for a time-varying price-cost markup in the Euro area inlation process

    Get PDF
    Empirical models of inflation often incorporate equilibrium correction effects based upon levels of prices and input costs. Such models assume that the steady-state price-cost markup is constant, but recent research suggests that this may not be true for the Euro area economy, which has undergone major structural reforms over the last 25 years. We allow for permanent shifts in the markup factor through estimating an inflation equation that includes a time-varying intercept. The model suggests that a reduction in the markup contributed to disinflation in the Euro area during the period 1981-2000.inflation, price-cost markup, cointegration, time-varying intercept, dynamic modelling.

    Ordering monomial factors of polynomials in the product representation

    Get PDF
    The numerical construction of polynomials in the product representation (as used for instance in variants of the multiboson technique) can become problematic if rounding errors induce an imprecise or even unstable evaluation of the polynomial. We give criteria to quantify the effects of these rounding errors on the computation of polynomials approximating the function 1/s1/s. We consider polynomials both in a real variable ss and in a Hermitian matrix. By investigating several ordering schemes for the monomials of these polynomials, we finally demonstrate that there exist orderings of the monomials that keep rounding errors at a tolerable level.Comment: Latex2e file, 7 figures, 32 page

    Wafer scale nano-membranes supported on a silicon microsieve

    Get PDF
    A new micromachining method to fabricate wafer scale, atomically smooth nano-membranes is described. The delicate membrane is supported on a robust silicon microsieve fabricated by plasma etching. The supporting sieve is micromachined independently of the nano-membrane, which is later fusion bonded to it. The transferred thin-film membrane can be dense, porous or perforated according to the application desired. One of the main application areas for such membranes is in fluidics, where the small thickness and high strength of the supported nano-membranes is a big advantage. The novel method described enables to easily up-scale and interface micro or nano-membranes to the macro-worl

    Hopping conductivity in heavily doped n-type GaAs layers in the quantum Hall effect regime

    Full text link
    We investigate the magnetoresistance of epitaxially grown, heavily doped n-type GaAs layers with thickness (40-50 nm) larger than the electronic mean free path (23 nm). The temperature dependence of the dissipative resistance R_{xx} in the quantum Hall effect regime can be well described by a hopping law (R_{xx} \propto exp{-(T_0/T)^p}) with p=0.6. We discuss this result in terms of variable range hopping in a Coulomb gap together with a dependence of the electron localization length on the energy in the gap. The value of the exponent p>0.5 shows that electron-electron interactions have to be taken into account in order to explain the occurrence of the quantum Hall effect in these samples, which have a three-dimensional single electron density of states.Comment: 5 pages, 2 figures, 1 tabl

    Injection and detection of spin in a semiconductor by tunneling via interface states

    Full text link
    Injection and detection of spin accumulation in a semiconductor having localized states at the interface is evaluated. Spin transport from a ferromagnetic contact by sequential, two-step tunneling via interface states is treated not in itself, but in parallel with direct tunneling. The spin accumulation induced in the semiconductor channel is not suppressed, as previously argued, but genuinely enhanced by the additional spin current via interface states. Spin detection with a ferromagnetic contact yields a weighted average of the spin accumulation in the channel and in the localized states. In the regime where the spin accumulation in the localized states is much larger than that in the channel, the detected spin signal is insensitive to the spin accumulation in the localized states and the ferromagnet probes the spin accumulation in the semiconductor channel.Comment: 7 pages, 2 figures. Theory onl

    Spectrally resolved single-shot wavefront sensing of broadband high-harmonic sources

    Full text link
    Wavefront sensors are an important tool to characterize coherent beams of extreme ultraviolet radiation. However, conventional Hartmann-type sensors do not allow for independent wavefront characterization of different spectral components that may be present in a beam, which limits their applicability for intrinsically broadband high-harmonic generation (HHG) sources. Here we introduce a wavefront sensor that measures the wavefronts of all the harmonics in a HHG beam in a single camera exposure. By replacing the mask apertures with transmission gratings at different orientations, we simultaneously detect harmonic wavefronts and spectra, and obtain sensitivity to spatiotemporal structure such as pulse front tilt as well. We demonstrate the capabilities of the sensor through a parallel measurement of the wavefronts of 9 harmonics in a wavelength range between 25 and 49 nm, with up to lambda/32 precision.Comment: 12 pages, 6 figure

    3D-melting features of the irreversibility line in overdoped Bi2_2Sr2_2CuO6_6 at ultra-low temperature and high magnetic field

    Full text link
    We have measured the irreversible magnetization of an overdoped Bi2_2Sr2_2CuO6_6 single crystal up to B=28 T and down to T=60 mK, and extracted the irreversibility line Birr(T)B_{\rm irr}(T): the data can be interpreted in the whole temperature range as a 3D-anisotropic vortex lattice melting line with Lindemann number cL=0.13c_{\rm L}=0.13. We also briefly discuss the applicability of alternative models such as 2D- and quantum melting, and the connection with magnetoresistance experiments.Comment: M2S-HTSC-VI Conference paper (2 pages, 1 figure), using Elsevier style espcrc2.st
    corecore