Cross-validating administrative and survey datasets through microsimulation and the assessment of a tax reform in Luxembourg

Using EUROMOD, we cross-validate two types of micro-data presently available in the Grand-Duchy of Luxembourg, administrative data on one hand and survey data on the other hand. While administrative data, extracted from the recently implemented Social Security Data Warehouse, contain information of the whole population of Luxembourg (449,000 observations) in 2003, survey data, extracted from the Luxembourg household panel PSELL3/EU-SILC for 2004 (incomes from 2003), is a representative sample of around 3,600 private households (9,800 individuals) living in Luxembourg with detailed information on incomes, household structure and other socio-economic dimensions. As a concrete application of this cross-validation, we analyze the 2001-2002 tax reform in Luxembourg. The main aspects of this reform are the reduction of the number of the tax brackets and the fall of the maximal marginal tax rate (from 46% in 2000 to 42% in 2001 and to 38% in 2002). The distributional effects of the tax reform are measured in terms of losers and winners, change in inequalities and poverty rates. The results issued from different types of input data are compared for cross-validation and allow us to emphasize methodological difficulties as well as to underline the advantages and limitations of each dataset.EUROMOD ; Microsimulation ; Tax reform ; Validation

Comptabilité générationnelle et vieillissement démographique : les enseignements d’un modèle d’équilibre général calculable calibré pour la Belgique

Dans la plupart des pays développés, un vieillissement démographique important s’annonce. À politique économique inchangée, ce vieillissement générera un accroissement important des charges supportées par les individus jeunes et actifs, présents et à venir, et donc une détérioration de la situation des générations futures. Dans ce débat, la comptabilité générationnelle d’Auerbach et al. (1991, 1994) et Kotlikoff (1992) occupe une place prépondérante. Elle permet, en effet, de comparer le bilan fiscal moyen des générations à venir avec la charge supportée par les générations actuelles. Nous proposons dans ce papier une extension immédiate de la comptabilité générationnelle d’Auerbach et al., qui consiste à estimer, de manière mécanique, la distribution de la charge léguée entre les générations futures. En supposant que la taxe sur les salaires équilibre le budget de l’État à chaque période, il ressort que ce sont les générations qui atteignent l’âge adulte entre 2020 et 2035 qui supportent la charge la plus forte. Les résultats sont établis sur base de données valables pour la Belgique. Puis nous comparons les enseignements de cette approche avec les résultats livrés par un modèle d’équilibre général dans lequel les agents ont une durée de vie incertaine. Ce type de modèle restitue un ensemble de grandeurs établies sur base d’hypothèses de comportement rationnel des individus et d’équilibre des marchés. Il nous montre que les écarts entre les charges supportées par les individus actuellement en vie et ceux à naître pourraient être beaucoup plus prononcés que ceux dégagés par une simple extrapolation mécanique. Cet effet est essentiellement dû à un rétrécissement des bases fiscales résultant d’une hausse du taux de taxation des salaires.In most developed countries, the age distribution of the population is shifting rapidly towards the elderly. If transfers and the tax schedule are unchanged, future generations will then have to bear an increased charge and, consequently, they could be deprived. This process is the subject of much debate, using tools like the Auerbach et al. (1991, 1993) and Kotlikoff's (1992) generational accounting. These aim to compare the mean charge to be borne by future generations with the net payments of the people presently alive. In this paper, we first propose an immediate extension of the Auerbach and Kotlikoff's standard generational accounting. We mechanically evaluate the distribution of the inherited charge between the future generations. If we suppose that the income tax is adapted on a yearly basis to meet the instantaneous public budget constraints, for a given debt ratio, people born at the beginning of the next century will be the most charged. These results are presented for the Belgian case. We then extend the Auerbach and Kotlikoff's standard generational accounting by developing a computable general equilibrium model with overlapping generations in which lifetime is uncertain. The general equilibrium approach yields results that are compatible with the hypothesis of an individual's rational behaviour and with the balancing of the markets. It is shown that the gap occurring between the charges borne by the present generations and the individuals to be born could be much higher than the one estimated through a simple mechanical methodology. This results from a shrinkage of the fiscal basis due to a higher tax on wages

Comptabilité générationnelle et vieillissement démographique : les enseignements d’un modèle d’équilibre général calculable calibré pour la Belgique

In most developed countries, the age distribution of the population is shifting rapidly towards the elderly. If transfers and the tax schedule are unchanged, future generations will then have to bear an increased charge and, consequently, they could be deprived. Dans la plupart des pays développés, un vieillissement démographique important s’annonce. À politique économique inchangée, ce vieillissement générera un accroissement important des charges supportées par les individus jeunes et actifs, présents et à venir, et donc une détérioration de la situation des générations futures. Dans ce débat, la comptabilité générationnelle d’Auerbach et al. (1991, 1994) et Kotlikoff (1992) occupe une place prépondérante. Elle permet, en effet, de comparer le bilan fiscal moyen des générations à venir avec la charge supportée par les générations actuelles.

A Model of Bacterial Intestinal Infections in Drosophila melanogaster

Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd)-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis

The ageing of the population and justice between generations: A GGE and generational accounting approach for Belgium

SCOPUS: ch.binfo:eu-repo/semantics/publishe

Essais en économie dynamique appliquée

Doctorat en sciences sociales, politiques et économiquesinfo:eu-repo/semantics/nonPublishe

Comptabilité générationnelle et équilibre général calculable: application au cas belge

info:eu-repo/semantics/publishe

Simulating computable overlapping generations models with TROLL

In this paper, we examine the performance of the TROLL stacked-time algorithm in the simulation of large scale overlapping generations (OLG) models. At each period of time, the number of equations is proportional to the individual length of lifetime. The model size and the data requirements may thus be very large. Given the repetitive structure of the equations, we show how TROLL specific macrocommands can be used to explode a generic version (in which the lifetime is parameterized) into a complete model. A similar technique applies to explode the initial dataset on the whole simulation horizon. The stability properties of the model are derived and the stacked-time algorithm performances are checked for a large scale model with endogenous labour supply and uncertain lifetime. It turns out that TROLL performances are very attractive even for a system of 300000 simultaneous equations. © 2004 Kluwer Academic Publishers.SCOPUS: ar.jinfo:eu-repo/semantics/publishe