A Note on the Dynamics of Persistence in US Inflation

Empirical research on the degree and stability of inflation persistence in the US has produced mixed results: some suggest high and unchanged persistence during the last few decades, while others argue in favor of a decline in persistence since the early 1980s. We show that post-WWII US inflation (monthly and quarterly) became highly persistent during the´Great Inflation´ period, and then switched back to a low persistence process during 1984, and has remained stationary until the present day.Inflation, Multiple change in persistence, Stationarity, Great inflation.

On the dynamics of inflation persistence around the world

We study the dynamics of inflation persistence in 45 countries for the period 1960-2008. We use a nonparametric unit root test robust to nonlinearities, error distributions, structural breaks and outliers, many of them typical features of inflation data, and a test for multiple changes in persistence, which decomposes the sample information between adjacent I(0) and I(1) periods. We find that (1) With very few exceptions, inflation around the world rejects a unit root, (2) for several countries there is evidence of significant changes in persistence, (3) bursts and drops in the level of inflation and in inflation persistence tend to coincide, (4) these drops occurred during “the Great Moderation” and during the adoption of inflation targeting. We conclude that inflation is characterized by either a stationary behaviour throughout the sample, or by switches of the type I(0)-I(1)-I(0). For all countries in our sample, any indication of nonstationarity seems to be temporary.Inflation, Multiple persistence change, Stationarity, Unit root tests, Unknown direction of change, Monetary policy

Time Series Approach to Test a Change in Inflation Persistence: The Mexican Experience.

When monetary policy has an explicit inflation target, observed inflation should be a stationary process. In countries where, for a variety of reasons, the determinants of inflation could lead it to follow a non-stationary process, the adoption of an inflation targeting framework should therefore induce a fundamental change in the stochastic process governing inflation. This paper studies the time series properties of Mexican inflation during 1995-2006, using recently developed techniques to detect a change in the persistence of economic time series. Consistent with the adoption of an inflation-targeting framework, the results suggest that inflation in Mexico seems to have switched from a nonstationary to a stationary process around the end of year 2000 or the beginning of 2001.Inflation, Persistence change, Stationarity, Unit root tests, Unknown direction of change

Finite density and temperature in hybrid bag models

We introduce the chemical potential in a system of two-flavored massless fermions in a chiral bag by imposing boundary conditions in the Euclidean time direction. We express the fermionic mean number in terms of a functional trace involving the Green function of the boundary value problem, which is studied analytically. Numerical evaluations for the fermionic number are presented.Comment: 19 pages, 4 figure

Distinguishing hypertension from hypertrophic cardiomyopathy as a cause of left ventricular hypertrophy

Distinguishing Hypertension From Hypertrophic Cardiomyopathy as aCause of Left Ventricular HypertrophyIn most hypertensive patients, left ventricular (LV) wallthickness is normal or only mildly increased (≤13 m

Confined two-dimensional fermions at finite density

We introduce the chemical potential in a system of two-dimensional massless fermions, confined to a finite region, by imposing twisted boundary conditions in the Euclidean time direction. We explore in this simple model the application of functional techniques which could be used in more complicated situations.Comment: 15 pages, LaTe

Massless fermions in a bag at finite density and temperature

We introduce the chemical potential in a system of massless fermions in a bag by impossing boundary conditions in the Euclidean time direction. We express the fermionic mean number in terms of a functional trace involving the Green's function of the boundary value problem, which we study analytically. Numerical evaluations are made, and an application to a simple hadron model is discussed.Comment: 14 pages, 3 figures, RevTe