8,981 research outputs found
Wage and Price Phillips Curves
In this paper we introduce a small Keynesian model of economic growth which is centered around two advanced types of Phillips curves, one for money wages and one for prices, both being augmented by perfect myopic foresight and supplemented by a measure of the medium-term inflationary climate updated in an adaptive fashion. The model contains two potentially destabilizing feedback chains, the so-called Mundell and Rose-effects. We estimate parsimonious and congruent Phillips curves for money wages and prices in the US over the past five decades. Using the parameters of the empirical Phillips curves, we show that the growth path of the private sector of the model economy is likely to be surrounded by centrifugal forces. Convergence to this growth path can be generated in two ways: a Blanchard-Katz-type error-correction mechanism in the money-wage Phillips curve or a modified Taylor rule that is augmented by a term, which transmits increases in the wage share (real unit labor costs) to increases in the nominal rate of interest. Thus the model is characterized by local instability of the wage-price spiral, which however can be tamed by appropriate wage or monetary policies. Our empirical analysis finds the error-correction mechanism being ineffective in both Phillips curves suggesting that the stability of the post-war US macroeconomy originates from the stabilizing role of monetary policy.Phillips curves, Mundell effect, Rose effect, monetary policy, Taylor rule, inflation, unemployment, instability
Wage and Price Phillips Curves An empirical analysis of destabilizing wage-price spirals
In this paper we introduce a small Keynesian model of economic growth which is centered around two advanced types of Phillips curves, one for money wages and one for prices, both being augmented by perfect myopic foresight and supplemented by a measure of the medium-term inflationary climate updated in an adaptive fashion. The model contains two potentially destabilizing feedback chains, the so-called Mundell and Rose-effects. We estimate parsimonious and congruent Phillips curves for money wages and prices in the US over the past five decades. Using the parameters of the empirical Phillips curves, we show that the growth path of the private sector of the model economy is likely to be surrounded by centrifugal forces. Convergence to this growth path can be generated in two ways: a Blanchard-Katz-type error-correction mechanism in the money-wage Phillips curve or a modified Taylor rule that is augmented by a term, which transmits increases in the wage share (real unit labor costs) to increases in the nominal rate of interest. Thus the model is characterized by local instability of the wage-price spiral, which however can be tamed by appropriate wage or monetary policies. Our empirical analysis finds the error-correction mechanism being ineffective in both Phillips curves suggesting that the stability of the post-war US macroeconomy originates from the stabilizing role of monetary policy.Phillips curves, Mundell effect, Rose effect, Monetary policy, Taylor Rule, Inflation, Unemployment, Instability
Analytic multivariate generating function for random multiplicative cascade processes
We have found an analytic expression for the multivariate generating function
governing all n-point statistics of random multiplicative cascade processes.
The variable appropriate for this generating function is the logarithm of the
energy density, ln epsilon, rather than epsilon itself. All cumulant statistics
become sums over derivatives of ``branching generating functions'' which are
Laplace transforms of the splitting functions and completely determine the
cascade process. We show that the branching generating function is a
generalization of the multifractal mass exponents. Two simple models from fully
developed turbulence illustrate the new formalism.Comment: REVTeX, 4 pages, 2 PostScript figs, submitted to PR
Mathematical modeling of the dynamics of a shovel with flexible coupling
To study the possible ergonomic and energetic advantages on the use of a shovel with a flexible coupling, a dynamic analysis of the motion of the blade together with the lifted raw material was conducted. By this dynamic analysis, ordinary differential equations were set up. Therefore the closed-form solutions were found to obtain useful equations for simulation. The application of mathematical modeling both to the blade with elastic coupling and to the traditional one, allowed to quantify the zeroing of the operator effort in the second half of the blade lifting. However, in the first part of the lifting an effort increase occurs, but in this first phase the operator can take advantage from the support on the thigh, thus lightening the load on the spine
PARSEC: A Parametrized Simulation Engine for Ultra-High Energy Cosmic Ray Protons
We present a new simulation engine for fast generation of ultra-high energy
cosmic ray data based on parametrizations of common assumptions of UHECR origin
and propagation. Implemented are deflections in unstructured turbulent
extragalactic fields, energy losses for protons due to photo-pion production
and electron-pair production, as well as effects from the expansion of the
universe. Additionally, a simple model to estimate propagation effects from
iron nuclei is included. Deflections in galactic magnetic fields are included
using a matrix approach with precalculated lenses generated from backtracked
cosmic rays. The PARSEC program is based on object oriented programming
paradigms enabling users to extend the implemented models and is steerable with
a graphical user interface.Comment: 10 pages, 6 figures, accepted for publication in Astroparticle
Physic
Modulated Natural Inflation
We discuss some model-independent implications of embedding (aligned) axionic
inflation in string theory. As a consequence of string theoretic duality
symmetries the pure cosine potentials of natural inflation are replaced by
modular functions. This leads to "wiggles" in the inflationary potential that
modify the predictions with respect to CMB-observations. In particular, the
scalar power spectrum deviates from the standard power law form. As a
by-product one can show that trans-Planckian excursions of the aligned
effective axion are compatible with the weak gravity conjecture.Comment: 8 pages, 6 figure
Natural Inflation and Low Energy Supersymmetry
Natural (axionic) inflation provides a well-motivated and predictive scheme
for the description of the early universe. It leads to sizeable primordial
tensor modes and thus a high mass scale of the inflationary potential. Naively
this seems to be at odds with low (TeV) scale supersymmetry, especially when
embedded in superstring theory. We show that low scale supersymmetry is
compatible with natural (high scale) inflation. The mechanism requires the
presence of two axions that are provided through the moduli of string theory.Comment: 15 pages, 4 figure
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