26,995 research outputs found
Testing for a time-varying price-cost markup in the Euro area inflation process
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
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
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
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 . We
consider polynomials both in a real variable 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
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
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
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
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 BiSrCuO at ultra-low temperature and high magnetic field
We have measured the irreversible magnetization of an overdoped
BiSrCuO single crystal up to B=28 T and down to T=60 mK, and
extracted the irreversibility line : the data can be
interpreted in the whole temperature range as a 3D-anisotropic vortex lattice
melting line with Lindemann number . 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
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