Measuring the Correlation of Shocks Between the UK and the Core of Europe

This paper considers the question of the symmetry of inflation and GDP shocks between the UK and the three major European EMU countries. It applies a relatively new technique, the orthogonal GARCH model, which allows us to calculate a complete time varying correlation matrix for these four countries. We can then examine the way the conditional correlation of shocks between the UK and the other European countries ahs been evolving over time. Our overall results Show that the shocks, which hit the UK, are now broadly symmetrical with France and Italy but that Germany seems to exhibit very low correlation with any of the other three countries.Shocks, EMU, Europe, GARCH

Inflation and business cycle convergence in the euro area: Empirical analysis using an unobserved component model

The optimum currency area literature highlights that large inflation differentials can undermine a monetary union. In the euro area, inflation rates diverged after the creation of the single currency, and started to converge again after mid 2002. Another point suggested by the literature is that business cycles are an important determinant of inflation differences across countries. Against this background, we assess the convergence of inflation rates and business cycles in the euro area and study the relationship between them. The analysis is done using unobserved component model estimated with the Kalman filter. In general, from 1980 to 2008, inflation rates and business cycles have become more aligned in the euro area. It is found that output gap is better than unit labour costs as an indicator of business cycle when studying convergence. We also conclude that inflation rates have converged faster than output gaps. When looking at the causality between the convergence of these two variables, it is found that the destabilising impact of inflation divergence is limited.FC

A Monte Carlo Study of Time Varying Coefficient (TVC) Estimation

A number of recent papers have proposed a time-varying-coefficient (TVC) procedure that, in theory, yields consistent parameter estimates in the presence of measurement errors, omitted variables, incorrect functional forms, and simultaneity. The key element of the procedure is the selection of a set of driver variables. With an ideal driver set the procedure is both consistent and efficient. However, in practice it is not possible to know if a perfect driver set exists. We construct a number of Monte Carlo experiments to examine the performance of the methodology under (i) clearly-defined conditions and (ii) a range of model misspecifications. We also propose a new Bayesian search technique for the set of driver variables underlying the TVC methodology. Experiments are performed to allow for incorrectly specified functional form, omitted variables, measurement errors, unknown nonlinearity and endogeneity. In all cases except the last, the technique works well in reasonably small samples. © 2018, The Author(s)

Approximate Deadline-Scheduling with Precedence Constraints

We consider the classic problem of scheduling a set of n jobs non-preemptively on a single machine. Each job j has non-negative processing time, weight, and deadline, and a feasible schedule needs to be consistent with chain-like precedence constraints. The goal is to compute a feasible schedule that minimizes the sum of penalties of late jobs. Lenstra and Rinnoy Kan [Annals of Disc. Math., 1977] in their seminal work introduced this problem and showed that it is strongly NP-hard, even when all processing times and weights are 1. We study the approximability of the problem and our main result is an O(log k)-approximation algorithm for instances with k distinct job deadlines

B-L-violating Masses in Softly Broken Supersymmetry

We prove a general low-energy theorem establishing a generic relation between the neutrino Majorana mass and the superpartner sneutrino B-L-violating "Majorana"-like mass term. The theorem states that, if one of these two quantities is non-zero the other one is also non-zero and, vice versa, if one of them vanishes the other vanishes, too. The theorem is a consequence of the underlying supersymmetry (SUSY) and valid for any realistic gauge model with weak scale softly broken SUSY.Comment: 7 pages, Latex, 1 Postscript figur

Energetic impact of size-selected metal cluster ions on graphite

We have investigated the impact of size-selected metal cluster ions (Agn-) on a covalently bonded substrate (graphite) over the energy range 15–1500 eV by a combination of scanning tunneling microscopy and molecular dynamics simulations. The key result is that the fate of the cluster (penetration into the surface versus diffusion and aggregation on the surface), at intermediate energies, depends on the lateral localization of the cluster kinetic energy at specific surface sites and thus, for small clusters, on the orientation of the cluster and the target substrate site

Curvature Diffusions in General Relativity

We define and study on Lorentz manifolds a family of covariant diffusions in which the quadratic variation is locally determined by the curvature. This allows the interpretation of the diffusion effect on a particle by its interaction with the ambient space-time. We will focus on the case of warped products, especially Robertson-Walker manifolds, and analyse their asymptotic behaviour in the case of Einstein-de Sitter-like manifolds.Comment: 34 page

Relating aviation service difficulty reports to accident data for safety trend prediction

A synthetic model of scheduled-commercial U.S. aviation fatalities was constructed from linear combinations of the time-spectra of critical systems reporting using 5.5 years of Service Difficulty Reports (SDR){sup 2} and Accident Incident Data System (AIDS) records{sup 3}. This model, used to predict near-future trends in aviation accidents, was tested by using the first 36 months of data to construct the synthetic model which was used to predict fatalities during the following eight months. These predictions were tested by comparison with the fatality data. A reliability block diagram (RBD) and third-order extrapolations also were used as predictive models and compared with actuality. The synthetic model was the best predictor because of its use of systems data. Other results of the study are a database of service difficulties for major aviation systems, and a rank ordering of systems according to their contribution to the synthesis. 4 refs., 8 figs., 3 tabs