Arbeidsaanbodelasticiteit en beleid

De invloed van beleidshervormingen op de werkgelegenheid is in belangrijke mate afhankelijk van de loonelasticiteit van het arbeidsaanbod. Ondanks de enorme hoeveelheid empirische studies is de hoogte van deze elasticiteit nog altijd onderwerp van discussie

What explains the Variation in Estimates of Labour Supply Elasticities?

This paper performs a meta-analysis of empirical estimates of uncompensated labour supply elasticities. We find that much of the variation in elasticities can be explained by the variation in gender, participation rates, and country fixed effects. Country differences appear to be small though. There is no systematic impact of the model specification or marital status on reported elasticities. The decision to participate is more responsive than is the decision regarding hours worked. Even at the intensive margin, we find that the elasticity for women exceeds that for men. For men and women in the Netherlands, we predict an uncompensated labour supply elasticity of 0.1 (or 0.2 if an alternative specification is preferred) and 0.5, respectively. These values are robust for alternative samples and specifications of the meta regression

Fiscaal beleid en arbeidsparticipatie

De Nederlandse overheid streeft naar een vergroting van de arbeidsdeelname en een verhoging van het kennisniveau van de beroepsbevolking. Dit moet bijdragen aan de betaalbaarheid van het stelsel van collectieve voorzieningen zodat solidariteit in de toekomst gewaarborgd kan blijven. Het belastingstelsel speelt hierbij een belangrijke rol. Immers, herverdelende belastingheffing vermindert de prikkels voor arbeidsaanbod en leren. Dit is echter een onvermijdelijk gevolg van het maatschappelijk streven naar het beperken van ongelijkheid. Toch zijn sommige vormen van herverdeling meer verstorend dan andere. Door slimme gerichte hervormingen kan het fiscale stelsel de negatieve effecten op de arbeidsdeelname verkleinen, zonder dat de koopkracht van de minstbedeelden daalt. Deze bijdrage onderzoekt dergelijke opties. Daarbij maken we gebruik van de inzichten uit de economische theorie alsook van simulaties met het MIMIC model van het CPB. De bijdrage richt zich in het bijzonder op drie doelgroepen: laaggeschoolden, vrouwen en ouderen

In-out charge exchange measurements and 3D modelling of diagnostic thermal neutrals to study edge poloidal impurity asymmetries

A new method was developed to model the neutral population produced by the gas puff based charge exchange recombination spectroscopy systems at ASDEX Upgrade (AUG). With this method, the edge impurity density on the high field side (HFS) and low field side (LFS) can be obtained without the need to apply a neutral beam injection system. The neutral penetration needed for the calculation of the impurity density is obtained with a new gas puff module implemented in the FIDASIM code. The LFS impurity density profile evaluated with the new gas puff module matches the impurity density calculated with standard beam-based charge exchange diagnostics. Impurity temperature, rotation and density profiles at the HFS and LFS of an AUG H-mode discharge are presented. Edge impurity toroidal and poloidal flows show asymmetric structures. The impurity density asymmetries obtained with the new gas puff module are consistent with the observed flow structure

Non-parametric inference of impurity transport coefficients in the ASDEX Upgrade tokamak

We present a non-parametric inference of impurity transport coefficients by using charge exchange recombination spectroscopy measurements of Ne X, Ne VIII, O VIII, and C VI lines. Due to their close atomic numbers, neon, oxygen and carbon impurity ions are assumed to have the same diffusion coefficient D and convection velocity v. Unlike conventional techniques that modulate or perturb the impurity contents, we employ a quasi-stationary plasma with static impurity profiles. Since the ratio of v to D only describes the equilibrated profile of the sum of all impurity charge states, steady-state measurements can still decouple D and v if different charge states are simultaneously observed. We have formulated a non-parametric analysis framework based on the Bayesian probability theory and conducted transport coefficient measurements for a Type III ELMy H-mode plasma at ASDEX Upgrade. The charge exchange reactions with the background neutrals, which are known to affect the impurity charge state balance, are taken into account by introducing additional free parameters. While D at the pedestal is close to the neoclassical level ( < 1 m s-2), a large diffusion coefficient and a strong outward convection are inferred right inside the pedestal top.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053

A global spectral library to characterize the world's soil

Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about soil to sustainably manage and preserve it for future generations. To this end, we developed and analyzed a global soil visible-near infrared (vis-NIR) spectral library. It is currently the largest and most diverse database of its kind. We show that the information encoded in the spectra can describe soil composition and be associated to land cover and its global geographic distribution, which acts as a surrogate for global climate variability. We also show the usefulness of the global spectra for predicting soil attributes such as soil organic and inorganic carbon, clay, silt, sand and iron contents, cation exchange capacity, and pH. Using wavelets to treat the spectra, which were recorded in different laboratories using different spectrometers and methods, helped to improve the spectroscopic modelling. We found that modelling a diverse set of spectra with a machine learning algorithm can find the local relationships in the data to produce accurate predictions of soil properties. The spectroscopic models that we derived are parsimonious and robust, and using them we derived a harmonized global soil attribute dataset, which might serve to facilitate research on soil at the global scale. This spectroscopic approach should help to deal with the shortage of data on soil to better understand it and to meet the growing demand for information to assess and monitor soil at scales ranging from regional to global. New contributions to the library are encouraged so that this work and our collaboration might progress to develop a dynamic and easily updatable database with better global coverage. We hope that this work will reinvigorate our community's discussion towards larger, more coordinated collaborations. We also hope that use of the database will deepen our understanding of soil so that we might sustainably manage it and extend the research outcomes of the soil, earth and environmental sciences towards applications that we have not yet dreamed of