Heavy-flavor suppression and azimuthal anisotropy in Pb-Pb collisions at sqrt(s_{NN}) = 2.76 TeV with the ALICE detector

Heavy-flavor hadron production studies in Pb-Pb collisions at sqrt(s_{NN}) = 2.76 TeV with the 2010 and 2011 data samples are presented. The measurements are performed with the ALICE detector in various decay channels and in a wide kinematic range. Heavy-flavor hadrons exhibit a suppression in the most central Pb-Pb collisions that amounts to a factor 3-5 for pT ~ 8-10 GeV/c. The second harmonic of the azimuthal distribution Fourier decomposition, v2, is non-zero for non-central collisions at intermediate pT (~3 GeV/c).Comment: Quark Matter 2012 proceeding

Open Heavy Flavor Production in p-p and Pb-Pb collisions as seen by ALICE at the LHC

Charm and beauty production are probed with the ALICE experiment at the LHC by studying the single lepton transverse momentum distribution (electrons at mid-rapidity, muons at large-rapidities) and D mesons reconstructed in their hadronic decays. The differential production cross sections in proton proton interactions show a good agreement with perturbative QCD calculations at both sqrt(s) = 2.76 and 7 TeV. The measurements in lead lead reactions at sqrt(s_{NN})= 2.76 TeV evidence a reduction (or suppression) of the production rate at intermediate and high pt in the most central collisions with respect to the rate in proton proton interactions.Comment: To appear in the Proceedings of the 19th Particles and Nuclei International Conference, PANIC 201

On the optimal progressivity of the income tax code

This paper computes the optimal progressivity of the income tax code in a dynamic general equilibrium model with household heterogeneity in which uninsurable labor productivity risk gives rise to a nontrivial income and wealth distribution. A progressive tax system serves as a partial substitute for missing insurance markets and enhances an equal distribution of economic welfare. These beneficial effects of a progressive tax system have to be traded off against the efficiency loss arising from distorting endogenous labor supply and capital accumulation decisions. Using a utilitarian steady state social welfare criterion we find that the optimal US income tax is well approximated by a flat tax rate of 17:2% and a fixed deduction of about $9,400. The steady state welfare gains from a fundamental tax reform towards this tax system are equivalent to 1:7% higher consumption in each state of the world. An explicit computation of the transition path induced by a reform of the current towards the optimal tax system indicates that a majority of the population currently alive (roughly 62%) would experience welfare gains, suggesting that such fundamental income tax reform is not only desirable, but may also be politically feasible. JEL Klassifikation: E62, H21, H24

Educational attainment and timing of fertility decisions

This paper focuses on timing of fertility decisions, conditional on the level of educational attainment of parents. Timing of fertility and educational attainment of parents rationalize the negative relationship observed in the data between hourly wages and childbearing. It is shown how the recent evolution in total fertility rates observed in developed countries could be in part the result of a transition from an early childbearing regime to a late childbearing regime. I develop a general equilibrium overlapping generations model in order to understand the joint determination of timing of childbearing decisions together with other household economic decisions in a life cycle framework. I show how idiosyncratic uncertainty might have asymmetric eects on completed fertility depending on timing of childbearing, generating the dierences in completed fertility observed between households that dier in their level of educational attainment.childbearing, overlapping generations, idiosyncratic uncertainty

Vintage specific learning-by-doing

This paper focuses on timing of fertility decisions, conditional on the level of educational attainment of parents. Timing of fertility and educational attainment of parents rationalize the negative relationship observed in the data between hourly wages and childbearing. It is shown how the recent evolution in total fertility rates observed in developed countries could be in part the result of a transition from an early childbearing regime to a late childbearing regime. I develop a general equilibrium overlapping generations model in order to understand the joint determination of timing of childbearing decisions together with other household economic decisions in a life cycle framework. I show how idiosyncratic uncertainty might have asymmetric eects on completed fertility depending on timing of childbearing, generating the dierences in completed fertility observed between households that dier in their level of educational attainment.childbearing, idiosyncratic, overlaping generations models, uncertainty

Taxing capital? : not a bad idea after all!

In this paper we quantitatively characterize the optimal capital and labor income tax in an overlapping generations model with idiosyncratic, uninsurable income shocks, where households also differ permanently with respect to their ability to generate income. The welfare criterion we employ is ex-ante (before ability is realized) expected (with respect to uninsurable productivity shocks) utility of a newborn in a stationary equilibrium. Embedded in this welfare criterion is a concern of the policy maker for insurance against idiosyncratic shocks and redistribution among agents of different abilities. Such insurance and redistribution can be achieved by progressive labor income taxes or taxation of capital income, or both. The policy maker has then to trade off these concerns against the standard distortions these taxes generate for the labor supply and capital accumulation decision. We find that the optimal capital income tax rate is not only positive, but is significantly positive. The optimal (marginal and average) tax rate on capital is 36%, in conjunction with a progressive labor income tax code that is, to a first approximation, a flat tax of 23% with a deduction that corresponds to about $6,000 (relative to an average income of households in the model of$35,000). We argue that the high optimal capital income tax is mainly driven by the life cycle structure of the model whereas the optimal progressivity of the labor income tax is due to the insurance and redistribution role of the income tax system. Klassifizierung: E62, H21, H2

La financiacion del Sistema de Seguridad Social en Espana: Efectos dinamicos de una posible reforma

Este articulo analiza los efectos de dos posibles reformas en la financiacion del actual sistema de Seguridad Social en Espana, y cuantifica los efectos de dichas reformas sobre los principales agregados macroeconomicos. El tipo de reformas que se analizan son la sustitucion del actual regimen de financiacion de cotizaciones, por imposicion directa e indirecta, y los efectos de variaciones en plazo de calculo de las pensiones de jubilacion. Para este proposito se construye un modelo de equilibrio general de generaciones sucesivas con agentes heterogeneos, calibrado para obtener resultados cuantitativos para el caso espanol. Encontramos que el actual sistema de financiacion es susceptible de mejora en su eficiencia, medida en terminos de variacion equivalente en el consumo, si se sustituye total o parcialmente por un regimen de impuestos indirectos. Cambios en el periodo de calculo de la pension afectan fundamentalmente a las decisiones temporales de ahorro/desahorro de los agentes.agentes heterogeneos, equilibrio general dinamico, seguridad social

On the Optimal Progressivity of the Income Tax Code

This paper computes the optimal progressivity of the income tax code in a dynamic general equilibrium model with household heterogeneity in which uninsurable labor productivity risk gives rise to a nontrivial income and wealth distribution. A progressive tax system serves as a partial substitute for missing insurance markets and enhances an equal distribution of economic welfare. These beneficial effects of a progressive tax system have to be traded off against the efficiency loss arising from distorting endogenous labor supply and capital accumulation decisions. Using a utilitarian steady state social welfare criterion we find that the optimal US income tax is well approximated by a flat tax rate of 17.2% and a fixed deduction of about $9,400. The steady state welfare gains from a fundamental tax reform towards this tax system are equivalent to 1.7% higher consumption in each state of the world. An explicit computation of the transition path induced by a reform of the current towards the optimal tax system indicates that a majority of the population currently alive (roughly 62%) would experience welfare gains, suggesting that such fundamental income tax reform is not only desirable, but may also be politically feasible.