Sluggish exports in advanced economies: How much is due to demand?

Exports in advanced economies have been relatively sluggish since 2011, growing at a much slower pace than observed before the global financial crisis. In this paper, export-demand equations for a panel of 18 countries in the Organisation for Economic Co-operation and Development (OECD) are estimated in order to assess whether this sluggishness can be attributed to weak foreign demand. Over half of the slowdown in advanced-economy export growth since 2011 (relative to the pre-crisis trend) can be explained by weak global demand growth. More specifically, exports in advanced economies have been restrained by the weakness of global investment, a trade-intensive demand component and weak demand out of Europe, a region that accounts for about 40 per cent of the demand for advanced-economy exports. Weak foreign demand cannot explain all of the weakness in aggregate OECD exports since 2011, suggesting that other factors have also played a role.Depuis 2011, la croissance des exportations des économies avancées a été relativement faible, nettement inférieure à celle observée avant la crise financière mondiale. Dans cette étude, l’auteur estime des équations de demande d’exportations pour un groupe de 18 pays membres de l’Organisation de coopération et de développement économiques (OCDE) en vue de déterminer si cette faiblesse est imputable à l’atonie de la demande étrangère. Plus de la moitié du ralentissement de la croissance des exportations des économies avancées enregistré depuis 2011 (relativement à leur progression tendancielle d’avant la crise) peut s’expliquer par la croissance timide de la demande mondiale. Plus particulièrement, les exportations des économies avancées ont été freinées par la faiblesse de l’investissement mondial, composante de la demande fortement dépendante des échanges, et par une demande anémique en Europe, région qui compte pour environ 40% de la demande d’exportations des économies avancées. La demande étrangère atone n’explique toutefois pas à elle seule la faiblesse des exportations globales des membres de l’OCDE constatée depuis 2011 : d’autres facteurs auraient joué un rôle

A probabilistic high cycle fatigue model applied to cast Al-Si alloys

In this work, the high cycle fatigue behavior of cast hypo-eutectic Al-Si alloys is investigated. It is observed that two different coexisting fatigue initiation mechanisms can occur in these materials depending on the presence of different microstructural heterogeneities (i.e. micro-shrinkage pores, Si particles, Fe-rich inter-metallics, DAS of the Al-matrix, etc).Firstly, an experimental study is presented, highlighting the coexistence of these two fatigue damage mechanisms and their dependence on the presence of different micro-structural heterogeneities. A probabilistic high cycle fatigue model, which has the capacity to describe these two mechanisms, is then presented. The model contains the same principal ingredients as the one developed by [1]. It uses a probabilistic framework to link the two different fatigue damage mechanisms, and can take into account the mean stress and the effect of a biaxial stress state.This work was undertaken in partnership with PSA Peugeot Citrooën and was financially supported by the French region, Pays de la Loire

A Systematic Search for Corotating Interaction Regions in Apparently Single Galactic Wolf-Rayet Stars. II. A Global View of the Wind Variability

This study is the second part of a survey searching for large-scale spectroscopic variability in apparently single Wolf-Rayet (WR) stars. In a previous paper (Paper I), we described and characterized the spectroscopic variability level of 25 WR stars observable from the northern hemisphere and found 3 new candidates presenting large-scale wind variability, potentially originating from large-scale structures named Co-rotating Interaction Regions (CIRs). In this second paper, we discuss an additional 39 stars observable from the southern hemisphere. For each star in our sample, we obtained 4-5 high-resolution spectra with a signal-to-noise ratio of ~100 and determined its variability level using the approach described in Paper I. In total, 10 new stars are found to show large-scale spectral variability of which 7 present CIR-type changes (WR 8, WR 44, WR 55, WR 58, WR 61, WR 63, WR 100). Of the remaining stars, 20 were found to show small-amplitude changes and 9 were found to show no spectral variability as far as can be concluded from the data in hand. Also, we discuss the spectroscopic variability level of all single galactic WR stars that are brighter than v~12.5, and some WR stars with 12.5 < v <= 13.5; i.e. all the stars presented in our two papers and 4 more stars for which spectra have already been published in the literature. We find that 23/68 stars (33.8 %) present large-scale variability, but only 12/54 stars (~22.1 %) are potentially of CIR-type. Also, we find 31/68 stars (45.6 %) that only show small-scale variability, most likely due to clumping in the wind. Finally, no spectral variability is detected based on the data in hand for 14/68 (20.6 %) stars. Interestingly, the variability with the highest amplitude also have the widest mean velocity dispersion.Comment: 14 pages, 24 figures, 2 tables, Accepted in Ap

Quantity, Quality, and Relevance: Central Bank Research, 1990-2003

The authors document the research output of 34 central banks from 1990 to 2003, and use proxies of research inputs to measure the research productivity of central banks over this period. Results are obtained with and without controlling for quality and for policy relevance. The authors find that, overall, central banks have been hiring more researchers and publishing more research since 1990, with the United States accounting for more than half of all published central bank research output, although the European Central Bank is rapidly establishing itself as an important research centre. When controlling for research quality and relevance, the authors generally find that there is no clear relationship between the size of an institution and its productivity. They also find preliminary evidence of positive correlations between the policy relevance and the scientific quality of central bank research. There is only very weak evidence of a positive correlation between the quantity of external partnerships and the productivity of researchers in central banks.Central bank research

Forecasting short-term real GDP growth in the euro area and Japan using unrestricted MIDAS regressions

In this paper, the authors develop a new tool to improve the short-term forecasting of real GDP growth in the euro area and Japan. This new tool, which uses unrestricted mixed-data sampling (U-MIDAS) regressions, allows an evaluation of the usefulness of a wide range of indicators in predicting short-term real GDP growth. In line with previous Bank studies, the results suggest that the purchasing managers' index (PMI) is among the best-performing indicators to forecast real GDP growth in the euro area, while consumption indicators and business surveys (the PMI and the Economy Watchers Survey) have the most predictive power for Japan. Moreover, the results indicate that combining the predictions from a number of indicators improves forecast accuracy and can be an effective way to mitigate the volatility associated with monthly indicators. Overall, our preferred U-MIDAS model specification performs well relative to various benchmark models and forecasters.Dans cette étude, les auteurs présentent l’outil qu’ils ont mis au point afin d’améliorer les prévisions de la croissance du PIB réel à court terme pour la zone euro et le Japon. Ce nouvel outil, qui s’appuie sur un modèle de régression fondé sur un échantillonnage de données de fréquence mixte sans contrainte (U-MIDAS), permet d’évaluer l’utilité d’une vaste gamme d’indicateurs pour prévoir la croissance du PIB réel à court terme. Corroborant les précédentes recherches menées par la Banque, les résultats de l’étude donnent à penser que l’indice des directeurs d’achat se classe parmi les indicateurs les plus performants pour prévoir la croissance du PIB réel à court terme dans la zone euro et que, dans le cas du Japon, les indicateurs de la consommation et les enquêtes réalisées auprès des entreprises (indice des directeurs d’achat et enquêtes auprès des observateurs de l’économie) ont le meilleur pouvoir prédictif. Les résultats montrent par ailleurs que la combinaison des prédictions tirées de plusieurs indicateurs améliore l’exactitude des prévisions et peut être un moyen efficace d’atténuer la volatilité associée aux indicateurs mensuels. Dans l’ensemble, la spécification du modèle U-MIDAS que les auteurs privilégient donne de bons résultats, par comparaison avec les prévisions de référence issues d’un groupe de modèles et de prévisionnistes

A comprehensive evaluation of measures of core inflation for Canada

This paper evaluates the usefulness of various measures of core inflation for the conduct of monetary policy. Traditional exclusion-based measures of core inflation are found to perform relatively poorly across a range of evaluation criteria, in part due to their inability to filter unanticipated transitory shocks. In contrast, measures such as the trimmed mean and the common component of CPI perform favorably, since they better capture persistent price movements and tend to move with macroeconomic drivers. All measures of core inflation, however, have limitations - consequently, there is merit in monitoring a set of measures. Moreover, core inflation measures are best viewed as complements to, rather than substitutes for, the thorough analysis of inflation and capacity pressures that informs the monetary policy process.Dans cette étude, les auteurs évaluent l’utilité de diverses mesures de l’inflation fondamentale pour la conduite de la politique monétaire. À la lumière de toute une série de critères d’évaluation, ils constatent que les mesures traditionnelles à exclusion de composantes font plutôt pâle figure, ce qui s’explique en partie par leur incapacité à faire abstraction des chocs temporaires inattendus. En revanche, les mesures telles que la moyenne tronquée et la composante commune de l’IPC (indice des prix à la consommation) se démarquent avantageusement, car elles saisissent mieux les variations durables des prix et suivent habituellement l’évolution des déterminants macroéconomiques. Toutes les mesures de l’inflation fondamentale présentent toutefois des lacunes. Il y a donc lieu de surveiller un ensemble de mesures. Par ailleurs, il vaut mieux reconnaître les mesures de l’inflation fondamentale non comme des substituts, mais comme des compléments à l’analyse approfondie de l’inflation et des pressions sur la capacité de production, analyse qui vient éclairer le processus d’élaboration de la politique monétaire

The common component of CPI: An alternative measure of underlying inflation for Canada

In this paper, the authors propose a measure of underlying inflation for Canada obtained from estimating a monthly factor model on individual components of the CPI. This measure, labelled the common component of CPI, has intuitive appeal and a number of interesting features. In particular, it is not affected by sector-specific price movements that can distort the signal in many other measures of underlying inflation, and appears to capture price movements that are indicative of aggregate demand fluctuations in the Canadian economy. This indicator may serve as a useful complement to existing measures of underlying inflation monitored by the Bank of Canada

An Investigation of the Large-scale Variability of the Apparently Single Wolf-Rayet Star WR 1

In recent years, much studies have focused on determining the origin of the large-scale line-profile and/or photometric patterns of variability displayed by some apparently single Wolf-Rayet stars, with the existence of an unseen (collapsed?) companion or of spatially extended wind structures as potential candidates. We present observations of WR 1 which highlight the unusual character of the variations in this object. Our narrowband photometric observations reveal a gradual increase of the stellar continuum flux amounting to Delta v = 0.09 mag followed by a decline on about the same timescale (3-4 days). Only marginal evidence for variability is found during the 11 following nights. Strong, daily line-profile variations are also observed but they cannot be easily linked to the photometric variations. Similarly to the continuum flux variations, coherent time-dependent changes are observed in 1996 in the centroid, equivalent width, and skewness of He II 4686. Despite the generally coherent nature of the variations, we do not find evidence in our data for the periods claimed in previous studies. While the issue of a cyclical pattern of variability in WR 1 is still controversial, it is clear that this object might constitute in the future a cornerstone for our understanding of the mechanisms leading to the formation of largely anisotropic outflows in Wolf-Rayet stars.Comment: 11 pages, 9 figures, accepted for publication in Astronomy & Astrophysic