413 research outputs found

    Exchange rate forecasting and the performance of currency portfolios

    Get PDF
    We examine the potential gains of using exchange rate forecast models and forecast combination methods in the management of currency portfolios for three exchange rates: the euro versus the US dollar, the British pound, and the Japanese yen. We use a battery of econometric specifications to evaluate whether optimal currency portfolios implied by trading strategies based on exchange rate forecasts outperform single currencies and the equally weighted portfolio. We assess the differences in profitability of optimal currency portfolios for different types of investor preferences, two trading strategies, mean squared error-based composite forecasts, and different forecast horizons. Our results indicate that there are clear benefits of integrating exchange rate forecasts from state-of-the-art econometric models in currency portfolios. These benefits vary across investor preferences and prediction horizons but are rather similar across trading strategies

    A dataset of human capital-weighted population estimates for 185 countries from 1970 to 2100

    Get PDF
    We provide a novel dataset of human capital-weighted population size (HCWP) for 185 countries from 1970 to 2100. HCWP summarizes a population's productive capacity and human capital heterogeneity in a single metric, enabling comparisons across countries and over time. The weights are derived from Mincerian earnings functions applied to multi-country census data on educational attainment. The model used to compute the returns to schooling accounts for the diminishing positive relative relationship between education and wages as the overall education of populations rises. The population weights are adjusted by a skills assessment factor representing differences in education quality across countries and years. HCWP is calculated by applying these adjusted human capital weights to population estimates and projections disaggregated by age, sex and education, spanning the period 1970-2020 and 2020-2100 for five Shared Socioeconomic Pathway scenarios. Validation analyses demonstrate the utility of the new HCWP data in explaining national income trends. As a more comprehensive population measure than basic size and age-sex indicators, HCWP enhances the power of statistical models aimed at the assessment of socioeconomic change impacts and forecasting

    Testing the chemical tagging technique with open clusters

    Get PDF
    Context. Stars are born together from giant molecular clouds and, if we assume that the priors were chemically homogeneous and well-mixed, we expect them to share the same chemical composition. Most of the stellar aggregates are disrupted while orbiting the Galaxy and most of the dynamic information is lost, thus the only possibility of reconstructing the stellar formation history is to analyze the chemical abundances that we observe today. Aims. The chemical tagging technique aims to recover disrupted stellar clusters based merely on their chemical composition. We evaluate the viability of this technique to recover co-natal stars that are no longer gravitationally bound. Methods. Open clusters are co-natal aggregates that have managed to survive together. We compiled stellar spectra from 31 old and intermediate-age open clusters, homogeneously derived atmospheric parameters, and 17 abundance species, and applied machine learning algorithms to group the stars based on their chemical composition. This approach allows us to evaluate the viability and efficiency of the chemical tagging technique. Results. We found that stars at different evolutionary stages have distinct chemical patterns that may be due to NLTE effects, atomic diffusion, mixing, and biases. When separating stars into dwarfs and giants, we observed that a few open clusters show distinct chemical signatures while the majority show a high degree of overlap. This limits the recovery of co-natal aggregates by applying the chemical tagging technique. Nevertheless, there is room for improvement if more elements are included and models are improved.Comment: accepted for publication in Astronomy and Astrophysics. Corrected typo

    Overcoming gender inequality for climate resilient development

    Get PDF
    Gender inequalities are reflected in differential vulnerability, and exposure to the hazards posed by climate change and addressing them is key to increase the adaptive capacities of societies. We provide trajectories of the Gender Inequality Index (GII) alongside the Shared-Socioeconomic Pathways (SSPs), a scenario framework widely used in climate science. Here we find that rapid improvements in gender inequality are possible under a sustainable development scenario already in the near-term. The share of girls growing up in countries with the highest gender inequality could be reduced to about 24% in 2030 compared to about 70% today. Largely overcoming gender inequality as assessed in the GII would be within reach by mid-century. Under less optimistic scenarios, gender inequality may persist throughout the 21st century. Our results highlight the importance of incorporating gender in scenarios assessing future climate impacts and underscore the relevance of addressing gender inequalities in policies aiming to foster climate resilient development

    Measuring Human Capital with Productivity-Weighted Labor Force: Methodology and Projections for China, India, the United States, and the European Union

    Get PDF
    This working paper provides a comprehensive overview of the methodology used to calculate a standardized and internationally comparable productivity-weighted labor force (PWLF) measure that takes into account both the education structure of the population and the quality of the educational system. Education-specific weights are calculated with a Mincerian earnings function on pooled data from all IPUMS-I censuses containing information on education, labor force status, and income. The education parameters are interacted with the countries' average educational attainment to account for the dependence of returns to education on the number of workers sharing that education level. Country and time specific adjustment factors for education quality are derived from skills assessment surveys. To calculate the productivity-weighted labor force size, these adjusted weights are then applied to labor force estimates and projections. The analytical value of the PWLF is validated making use of prediction exercise for GDP growth applied to a panel dataset covering all countries of the world from 1970 to 2015 for which data are available. Finally, the paper provides a practical application by forecasting PWLF figures for China, India, the United States, and the European Union from 2020 to 2100. These forecasts are compared against other population indicators (total population size, working-age population, and labor force size), highlighting the importance of population heterogeneity in the analysis of demographic trends

    AplicaciĂłn del paradigma MDE para la generaciĂłn de pruebas funcionales: Experiencia dentro del proyecto AQUA-WS

    Get PDF
    La fase de pruebas es uno de las más críticas en Ingeniería de Software. Durante esta fase, el equipo de desarrollo tiene que asegurar que el sistema cubre las necesidades y las expectativas del cliente y de los usuarios finales. Este trabajo presenta una visión global de NDT (Navigational Development Techniques) que usa el paradigma MDE (Model-Driven Engineering, ingeniería Guiada por Modelos) para generar casos de pruebas a partir la definición de los requisitos funcionales del proyecto. Este trabajo analiza este proceso y expone cómo se ha aplicado en el proyecto AQUA-WS: un proyecto real que actualmente usa este proceso.Ministerio de Educación y Ciencia TIN2007-67843-C06_03Ministerio de Ciencia e Innovación TIN2010-20057-C03-02Ministerio de Ciencia e Innovación TIN2010-12312-

    The Gaia-ESO Survey : The analysis of high-resolution UVES spectra of FGK-type stars

    Get PDF
    Date of Acceptance: 01/09/2014Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 105 stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already observed 1447 FGK-type stars. Aims. These UVES spectra are analyzed in parallel by several state-of-the-art methodologies. Our aim is to present how these analyses were implemented, to discuss their results, and to describe how a final recommended parameter scale is defined. We also discuss the precision (method-to-method dispersion) and accuracy (biases with respect to the reference values) of the final parameters. These results are part of the Gaia-ESO second internal release and will be part of its first public release of advanced data products. Methods. The final parameter scale is tied to the scale defined by the Gaia benchmark stars, a set of stars with fundamental atmospheric parameters. In addition, a set of open and globular clusters is used to evaluate the physical soundness of the results. Each of the implemented methodologies is judged against the benchmark stars to define weights in three different regions of the parameter space. The final recommended results are the weighted medians of those from the individual methods. Results. The recommended results successfully reproduce the atmospheric parameters of the benchmark stars and the expected Teff-log g relation of the calibrating clusters. Atmospheric parameters and abundances have been determined for 1301 FGK-type stars observed with UVES. The median of the method-to-method dispersion of the atmospheric parameters is 55 K for Teff, 0.13 dex for log g and 0.07 dex for [Fe/H]. Systematic biases are estimated to be between 50-100 K for Teff, 0.10-0.25 dex for log g and 0.05-0.10 dex for [Fe/H]. Abundances for 24 elements were derived: C, N, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, Nd, and Eu. The typical method-to-method dispersion of the abundances varies between 0.10 and 0.20 dex. Conclusions. The Gaia-ESO sample of high-resolution spectra of FGK-type stars will be among the largest of its kind analyzed in a homogeneous way. The extensive list of elemental abundances derived in these stars will enable significant advances in the areas of stellar evolution and Milky Way formation and evolution.Peer reviewe

    Convergence Without Hard Criteria: Does EU Soft Law Affect Domestic Unemployment Protection Schemes?

    Get PDF
    (VLID)177126
    • …
    corecore