780 research outputs found
Couts et benefices du passage d'une faible inflation a la stabilite des prix. Une comparaison internationale.
Cet article Ă©value, en reprenant l'approche de Feldstein [1996], quelques-uns des coĂ»ts et des bĂ©nĂ©fices du passage d'une faible inflation (2%) Ă une inflation nulle pour les Ă©conomies française, allemande, britannique, espagnole et amĂ©ricaine. Cette approche met l'accent sur les distorsions dans les dĂ©cisions d'Ă©pargne et d'investissement en logement engendrĂ©es par l'indexation imparfaite du systĂšme fiscal. Des Ă©tudes rĂ©centes ont montrĂ© qu'un passage d'une inflation de 2% Ă la stabilitĂ© des prix conduisait Ă des gains en surplus des mĂ©nages de l'ordre de 1,05% du PIB par an aux Etats-Unis, de 1,4% en Allemagne, de 1,7% en Espagne et de seulement 0,21% au Royaume-Uni. Nous montrons que ces diffĂ©rences d'Ă©valuation relĂšvent en grande partie du choix de l'Ă©lasticitĂ© de l'Ă©pargne au taux d'intĂ©rĂȘt et de spĂ©cificitĂ©s de la fiscalitĂ© de ces pays. En France, sur la base de la fiscalitĂ© de l'Ă©pargne prĂ©valant en 1998, le bĂ©nĂ©fice annuel du retour observĂ© Ă la stabilitĂ© des prix serait de 0,66%.Inflation ; prix ; cycles economiques.
Pitfalls in Investment Euler Equations.
This paper investigates three pitfalls concerning the test of the Euler equation facing quadratic adjustment costs and perfect capital markets on a large balanced panel data of 4025 french firms. First, the quadratic parameterization of adjustment costs is too restrictive, and power series approximations of adjustment costs are tested. Second, we isolate firms whose optimal Euler condition is not altered even in the presence of fixed adjustment costs. Third, we identify instruments which contribute to model failure via standard GMM\ tests. These methods point that financial instruments contribute to reject strongly the standard model, which shows that it is misspecified.Investment ; adjustment costs ; financial constraints ; generalized method of moments.
Firm Investment and Monetary Policy Transmission in the Euro Area.
We present a comparable set of results on the monetary transmission channels on firm investment for the four largest euro-area countries (Germany, France, Italy and Spain). With particularly rich micro datasets for each country containing over 215,000 observations from 1985 to 1999, we ex-plore what can be learned about the interest channel and the broad credit channel. For each of those countries, we estimate neo-classical investment relationships, explaining investment by its user cost, sales and cash flow. We find investment to be sensitive to user cost changes in all those four countries. This implies an operative interest channel in these euro-area countries. We also find in-vestment in all countries to be quite sensitive to cash flow movements. However, only in Italy do smaller firms react more to cash flow movements than large firms, implying that a broad credit channel might not be equally pervasive in all countries.Investment, Monetary transmission channels, User cost of capital.
Optimal Capacity in the Banking Sector and Economic Growth.
The paper investigates, from the welfare and growth point of view, the determination of the optimal capacity of the banking system. For that purpose, we consider an overlapping generation model with endogenous growth. There is horizontal differentiation and imperfect competition in the banking sector. Macroeconomic shocks affect the return on capital and, together with the expectations of depositors, condition the stability of the banking sector. We specify to what extent deposit insurance may reduce instability and increase the number of deposits, welfare and growth. We also characterize the conditions under which excess banking capacities may appear and how their reduction may improve welfare.Deposit insurance ; imperfect ; competition ; growth, banking.
Critical Behavior and Lack of Self Averaging in the Dynamics of the Random Potts Model in Two Dimensions
We study the dynamics of the q-state random bond Potts ferromagnet on the
square lattice at its critical point by Monte Carlo simulations with single
spin-flip dynamics. We concentrate on q=3 and q=24 and find, in both cases,
conventional, rather than activated, dynamics. We also look at the distribution
of relaxation times among different samples, finding different results for the
two q values. For q=3 the relative variance of the relaxation time tau at the
critical point is finite. However, for q=24 this appears to diverge in the
thermodynamic limit and it is ln(tau) which has a finite relative variance. We
speculate that this difference occurs because the transition of the
corresponding pure system is second order for q=3 but first order for q=24.Comment: 9 pages, 13 figures, final published versio
Critical Behavior of the Random Potts Chain
We study the critical behavior of the random q-state Potts quantum chain by
density matrix renormalization techniques. Critical exponents are calculated by
scaling analysis of finite lattice data of short chains () averaging
over all possible realizations of disorder configurations chosen according to a
binary distribution. Our numerical results show that the critical properties of
the model are independent of q in agreement with a renormalization group
analysis of Senthil and Majumdar (Phys. Rev. Lett.{\bf 76}, 3001 (1996)). We
show how an accurate analysis of moments of the distribution of magnetizations
allows a precise determination of critical exponents, circumventing some
problems related to binary disorder. Multiscaling properties of the model and
dynamical correlation functions are also investigated.Comment: LaTeX2e file with Revtex, 9 pages, 8 eps figures, 4 tables; typos
correcte
Digital videodensitometric measurement of aortic regurgitation
A videodensitometric method for quantification of aortic regurgitation which requires neither measurement of cardiac output nor determination of enddiastolic and endsystolic left ventricular volumes has been developed. The injection of 20 ml of contrast medium into the left ventricle is digitally recorded at 25 images sâ1 during 20 s using an equipment for digital subtraction angiography (Digitron 2, Siemens). The Digitron computes 2 âtime dilution curves' (TDC) from the unsubtracted image sequence, for 2 regions of interest drawn around the angiographic enddiastolic and endsystolic left ventricular silhouettes. Enddiastolic and endsystolic points of the TDC are then entered into a VAX-750 computer, which calculates the ejection fraction (EF), the forward ejection fraction (FEF) and the regurgitant fraction (RGF). This is performed by a complex fitting algorithm based on a physical model of the washout process of contrast medium, which reconstructs the two best enddiastolic and endsystolic baselines in the washout parts of the two TDC. The EF, FEF and RGF obtained in 9 regurgitant and 11 nonregurgitant patients have been compared with the corresponding values EFv, FEFv and RGFv obtained by a conventional technique (Cardiogreen and biplane LV area-length volumetry). Regression analysis yielded: EF = 0.88 Ă EFv (regression line forced through the origin), r = 0.77, FEF = 0.76 Ă FEFv + 3, r = 0.96, RGF = 0.94 Ă RGFv + 5, r = 0.98 (v stands for volumetry
Symmetry relation for multifractal spectra at random critical points
Random critical points are generically characterized by multifractal
properties. In the field of Anderson localization, Mirlin, Fyodorov,
Mildenberger and Evers [Phys. Rev. Lett 97, 046803 (2006)] have proposed that
the singularity spectrum of eigenfunctions satisfies the exact
symmetry at any Anderson transition. In the
present paper, we analyse the physical origin of this symmetry in relation with
the Gallavotti-Cohen fluctuation relations of large deviation functions that
are well-known in the field of non-equilibrium dynamics: the multifractal
spectrum of the disordered model corresponds to the large deviation function of
the rescaling exponent along a renormalization trajectory
in the effective time . We conclude that the symmetry discovered on
the specific example of Anderson transitions should actually be satisfied at
many other random critical points after an appropriate translation. For
many-body random phase transitions, where the critical properties are usually
analyzed in terms of the multifractal spectrum and of the moments
exponents X(N) of two-point correlation function [A. Ludwig, Nucl. Phys. B330,
639 (1990)], the symmetry becomes , or equivalently
for the anomalous parts .
We present numerical tests in favor of this symmetry for the 2D random
state Potts model with various .Comment: 15 pages, 3 figures, v2=final versio
Logarithmic corrections in the aging of the fully-frustrated Ising model
We study the dynamics of the critical two-dimensional fully-frustrated Ising
model by means of Monte Carlo simulations. The dynamical exponent is estimated
at equilibrium and is shown to be compatible with the value . In a
second step, the system is prepared in the paramagnetic phase and then quenched
at its critical temperature . Numerical evidences for the existence of
logarithmic corrections in the aging regime are presented. These corrections
may be related to the topological defects observed in other fully-frustrated
models. The autocorrelation exponent is estimated to be as for the
Ising chain quenched at .Comment: 12 pages, 9 figure
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