Aggregate employment, job polarization and inequalities: A transatlantic perspective

This paper develops a multi-sectorial search and matching model with endogenous occupational choice in a context of structural change. Our objective is to shed light on the way labor market institutions affect aggregate employment, job polarization and inequalities observed in the US and in European countries. We consider the cases of the US, France and Germany that are representative of alternative institutional settings, having the potential to induce divergent time-paths in the evolution of labor market outcomes during the process of technological transition. In the US and in Germany, we find employment gains from technological change and job polarization, whereas, in France, the technological change reduces aggregate employment in a context of job polarization. In the US, an half of these employment gains are due to the technological change, and the other half to the changes in the LMI, the contribution of the rise in share of skilled worker being negligible. In France, the change in LMI affects new job opportunities in manual jobs: the reallocation of routine workers towards manual jobs is obstructed for want of job creations of manual services. Hence, without technological change, the fall in French employment would have been cut by 70%. The model also predicts that, without the increase in skilled labor supply, the fall in French employment would have doubled. The improvement in educational attainment dampened the unfavorable consequences of technological change. we show that Germany transforms this structural change in employment gains, only after the labor reforms implemented after the middle of the 90s

The Italian National Project of Astrobiology-Life in Space-Origin, Presence, Persistence of Life in Space, from Molecules to Extremophiles

The \u2018\u2018Life in Space\u2019\u2019 project was funded in the wake of the Italian Space Agency\u2019s proposal for the development of a network of institutions and laboratories conceived to implement Italian participation in space astrobiology experiments

The Hexamer Structure of the Rift Valley Fever Virus Nucleoprotein Suggests a Mechanism for its Assembly into Ribonucleoprotein Complexes

Rift Valley fever virus (RVFV), a Phlebovirus with a genome consisting of three single-stranded RNA segments, is spread by infected mosquitoes and causes large viral outbreaks in Africa. RVFV encodes a nucleoprotein (N) that encapsidates the viral RNA. The N protein is the major component of the ribonucleoprotein complex and is also required for genomic RNA replication and transcription by the viral polymerase. Here we present the 1.6 Å crystal structure of the RVFV N protein in hexameric form. The ring-shaped hexamers form a functional RNA binding site, as assessed by mutagenesis experiments. Electron microscopy (EM) demonstrates that N in complex with RNA also forms rings in solution, and a single-particle EM reconstruction of a hexameric N-RNA complex is consistent with the crystallographic N hexamers. The ring-like organization of the hexamers in the crystal is stabilized by circular interactions of the N terminus of RVFV N, which forms an extended arm that binds to a hydrophobic pocket in the core domain of an adjacent subunit. The conformation of the N-terminal arm differs from that seen in a previous crystal structure of RVFV, in which it was bound to the hydrophobic pocket in its own core domain. The switch from an intra- to an inter-molecular interaction mode of the N-terminal arm may be a general principle that underlies multimerization and RNA encapsidation by N proteins from Bunyaviridae. Furthermore, slight structural adjustments of the N-terminal arm would allow RVFV N to form smaller or larger ring-shaped oligomers and potentially even a multimer with a super-helical subunit arrangement. Thus, the interaction mode between subunits seen in the crystal structure would allow the formation of filamentous ribonucleocapsids in vivo. Both the RNA binding cleft and the multimerization site of the N protein are promising targets for the development of antiviral drugs

Contraindications of sentinel lymph node biopsy: Áre there any really?

BACKGROUND: One of the most exciting and talked about new surgical techniques in breast cancer surgery is the sentinel lymph node biopsy. It is an alternative procedure to standard axillary lymph node dissection, which makes possible less invasive surgery and side effects for patients with early breast cancer that wouldn't benefit further from axillary lymph node clearance. Sentinel lymph node biopsy helps to accurately evaluate the status of the axilla and the extent of disease, but also determines appropriate adjuvant treatment and long-term follow-up. However, like all surgical procedures, the sentinel lymph node biopsy is not appropriate for each and every patient. METHODS: In this article we review the absolute and relative contraindications of the procedure in respect to clinically positive axilla, neoadjuvant therapy, tumor size, multicentric and multifocal disease, in situ carcinoma, pregnancy, age, body-mass index, allergies to dye and/or radio colloid and prior breast and/or axillary surgery. RESULTS: Certain conditions involving host factors and tumor biologic characteristics may have a negative impact on the success rate and accuracy of the procedure. The overall fraction of patients unsuitable or with multiple risk factors that may compromise the success of the sentinel lymph node biopsy, is very small. Nevertheless, these patients need to be successfully identified, appropriately advised and cautioned, and so do the surgeons that perform the procedure. CONCLUSION: When performed by an experienced multi-disciplinary team, the SLNB is a highly effective and accurate alternative to standard level I and II axillary clearance in the vast majority of patients with early breast cancer

The importance of timevaryingparametersin new Keynesian modelswith zero lower bound

In this paper we question the ability of New Keynesian models to reproduce the behavior of the nominal interest rate. In particular, we wonder if the model is able to reproduce infrequent but long ZLB spells as observed in the data. Starting from the canonical model, we compare alternative specifications like exogenous and endoge- nous time-varying parameters. We solve the different models with global approxima- tion methods and estimate them using the simulated method of moments. While the canonical model fails to reproduce typical ZLB spells, the endogenous time-varying parameters specification seems to be a promising avenue for research. We draw the implications of the alternative model’s specifications for the understanding of the mon- etary policy during ZLB episodes

Discount Factor Shocksand Labor MarketDynamics

In this paper we investigate the labor market dynamics in a matching model where fluctuations are driven by movements in the discount factor. A comparison with the standard productivity shock is provided. Movements in the discount factor can be used as a proxy for variations in financial risks, especially the expected payoff from hiring workers. It is shown that the canonical matching model under a very standard calibration is able to generate an important volatility of unemployment and vacancies with respect to output. We estimate the structural model with the two shocks and using the Bayesian methodology. The bulk of variations in unemployment and vacancies is mainly explained by disturbances pertaining to the discount factor. Productivity shocks account for most of the historical output variations but the discount factor plays a more important role over the last two decades

Rigidité du marché du travail et dynamique du chômage

Les rigidités du marché du travail ont souvent fait l’objet de spéculations dans la littérature en réponse à la volatilité excessive du chômage. Les questions d’économie positive mais aussi les questions normatives liées au fonctionnement des institutions du marché du travail ont animé un important débat. Cependant, les deux aspects du débat n’ont été que très peu orientés sur les interactions entre ces rigidités et la configuration optimale des institutions. L’objectif de cette thèse est de mettre en lumière le rôle de ces rigidités sur la dynamique du chômage et de l’inflation. On s’intéresse aux sources de fluctuations du marché du travail ainsi qu’aux questions liées au financement de l’assurance chômage en privilégiant les systèmes d’experience rating. Les résultats principaux sont les suivants. Premièrement, la prise en compte de frictions d’appariement et de rigidités de salaires est cruciale pour expliquer la dynamique du marché du travail mais leur estimation révèle que les chocs spécifiques au marché du travail comptabilisent une partie importante des fluctuations du chômage et des emplois vacants, impliquant une certaine déconnection avec les autres marchés. Deuxièmement, les systèmes d’assurance chômage basés sur l’experience rating stabilisent fortement les fluctuations du marché du travail en réduisant de façon considérable la volatilité du chômage et des séparations d’emplois mais également le coût en bien être associé aux imperfections du marché du travail. La prise en compte des non linéarités de ces systèmes permet de rendre compte des distorsions dans le comportement d’embauche et de licenciement des entrepreneurs.The excessive volatility of unemployment has raised an intense debate on the positive and the normative aspects of labor market rigidities and labor market institutions. However, on both sides of the debate there is little discussion on how rigidities interact with each other nor on the optimal design of institutions. The purpose of this thesis is to highlight the role of labor market rigidities for unemployment and inflation dynamics. We are interested in the sources of labor market fluctuations as well as the unemployment insurance financing mode. We focus on experience rating systems. The main results are the followings. First, matching frictions and wage rigidities are crucial to explain the labor market dynamics but estimations of structural models show that the bulk of variation in labor market variables is solely explained by disturbances pertaining to the labor market. Second, unemployment insurance experience rating systems reduce considerably the volatility of labor market outcomes and the welfare cost coming from labor market imperfections. The tax schedule of experience rating is highly non linear, which induce sizeable distortions in the firms' hiring and firing behavior

Taux de cotisation patronale à l'assurance chômage et dynamique du marché du travail

International audienc

Frictions or deadlocks? Job polarization with search and matching frictions

This paper extends Pissarides (1990)’s matching model by considering two sectors (routine and manual) and workers’ occupational choices, in the context of skill-biased demand shifts, to the detriment of routine jobs and in favour of manual jobs because of technological changes. The theoretical challenge is to investigate the reallocation process from the middle towards the bottom of the wage distribution. By using this framework, we shed light on the way in which labour market institutions affect the job polarization observed in the United States and Europe. The results of our quantitative experiments suggest that search frictions have non-trivial effects on the reallocation process and transitional dynamics of aggregate employment