Commentary on "Optimal monetary policy under uncertainty: a Markov jump-linear-quadratic approach"

Econometric models ; Monetary policy

Dynamics of Black Hole Pairs II: Spherical Orbits and the Homoclinic Limit of Zoom-Whirliness

Spinning black hole pairs exhibit a range of complicated dynamical behaviors. An interest in eccentric and zoom-whirl orbits has ironically inspired the focus of this paper: the constant radius orbits. When black hole spins are misaligned, the constant radius orbits are not circles but rather lie on the surface of a sphere and have acquired the name "spherical orbits". The spherical orbits are significant as they energetically frame the distribution of all orbits. In addition, each unstable spherical orbit is asymptotically approached by an orbit that whirls an infinite number of times, known as a homoclinic orbit. A homoclinic trajectory is an infinite whirl limit of the zoom-whirl spectrum and has a further significance as the separatrix between inspiral and plunge for eccentric orbits. We work in the context of two spinning black holes of comparable mass as described in the 3PN Hamiltonian with spin-orbit coupling included. As such, the results could provide a testing ground of the accuracy of the PN expansion. Further, the spherical orbits could provide useful initial data for numerical relativity. Finally, we comment that the spinning black hole pairs should give way to chaos around the homoclinic orbit when spin-spin coupling is incorporated.Comment: 16 pages, several figure

Identifying the influences of nominal and real rigidities in aggregate price-setting behavior

We formulate a generalized price-setting framework that incorporates staggered contracts of multiple durations and that enables us to directly identify the influences of nominal vs. real rigidities. Using German macroeconomic data over the period 1975Q1 through 1998Q4 toestimate this framework, we find that the data is well-characterized by a truncated Calvostyle distribution with an average duration of about two quarters. We also find that new contracts exhibit very low sensitivity to marginal cost, corresponding to a relatively high degree of real rigidity. Finally, our results indicate that backward-looking behavior is not needed to explain the aggregate data, at least in an environment with a stable monetary policy regime and a transparent and credible inflation objective. JEL Classification: E31, E52Inflation persistence, nominal rigidity, overlapping contracts, real rigidity, simulation-based indirect inference

Inflation persistence and monetary policy design: an overview

How monetary policy should be set optimally when the structure of the economy exhibits inflation persistence is an important question for policy makers. This paper provides an overview of the implications of inflation persistence for the design of monetary policy. JEL Classification: E52, E58Inflation persistence, optimal monetary policy, uncertainty

Inverse spectral results for Schr\"odinger operators on the unit interval with potentials in L^P spaces

We consider the Schr\"odinger operator on $[0,1]$ with potential in $L^1$. We prove that two potentials already known on $[a,1]$ ($a\in(0,{1/2}]$) and having their difference in $L^p$ are equal if the number of their common eigenvalues is sufficiently large. The result here is to write down explicitly this number in terms of $p$ (and $a$) showing the role of $p$

Why charges go to the surface: a generalized Thomson problem

We study a generalization of a Thomson problem of n particles confined to a sphere and interacting by a 1/r^g potential. It is found that for g \le 1 the electrostatic repulsion expels all the charges to the surface of the sphere. However for g>1 and n>n_c(g) occupation of the bulk becomes energetically favorable. It is curious to note that the Coulomb law lies exactly on the interface between these two regimes

Is inflation persistence intrinsic in industrial economies?

We apply both classical and Bayesian econometric methods to characterize the dynamic behavior of inflation for twelve industrial countries over the period 1984-2003, using four different price indices for each country. In particular, we estimate a univariate autoregressive (AR) model for each series, and consider the possibility of a structural break at an unknown date. For many of these countries, we find strong evidence for a break in the intercept of the AR equation in the late 1980s or early 1990s. Allowing for a break in intercept, the inflation measures generally exhibit relatively low inflation persistence. Evidently, high inflation persistence is not an inherent characteristic of industrial economies.Inflation (Finance)

Assessing the potential for food-based strategies to reduce Vitamin A and iron deficiencies

This paper reviews current knowledge and experience with food-based approaches to reduce vitamin A and iron deficiencies. It presents a review of recently published literature, highlights some of the lessons learned, and identifies knowledge gaps and research priorities. Plant breeding strategies are also discussed because of their potential to increase the content of vitamin A and iron in the diet as well as their bioavailability. populations. The same question as that posed in previous reviews decades ago remains at the end of the present review: what really can be achieved with food-based interventions to control vitamin A and iron deficiency? Food based approaches could be an essential part of the long-termglobal strategy to alleviate micronutrient deficiencies but their real potential is still to be explored.Minerals in human nutrition. ,Nutrition. ,Plant breeding. ,

Is inflation persistence intrinsic in industrial economies?

We apply both classical and Bayesian econometric methods to characterize the dynamic behavior of inflation for twelve industrial countries over the period 1984-2003, using four different price indices for each country. In particular, we estimate a univariate autoregressive (AR) model for each series, and consider the possibility of a structural break at an unknown date. For many of these countries, we find strong evidence for a break in the intercept of the AR equation in the late 1980s or early 1990s. Allowing for a break in intercept, the inflation measures generally exhibit relatively low inflation persistence. Evidently, high inflation persistence is not an inherent characteristic of industrial economies. JEL Classification: C11, C22, E31Bayesian econometrics, Inflation Dynamics, largest autoregressive root