The Micro and Macro of Labor Market Policies

This dissertation documents new evidence on the effects of labor market institutions and provides new tools to assess the impact of labor policies. Many labor market regulations remain controversial, and we lack evidence connecting the impact of these regulations on firms and workers and their aggregate effects. The dissertation evaluates the effects of labor market reforms at the microeconomic level (on workers and firms) and at the aggregate level (on overall employment, welfare, and the unemployment rate). It also accounts for spillovers, general equilibrium effects and heterogeneity to connect the micro and macro impacts. Relying on administrative data on workers and firms and reduced-form evaluation methods, I provide evidence on the effects of labor market policies on targeted individuals and firms, but also on the indirect effects. Second, to quantify the aggregate impact accounting for both direct and indirect effects, I build and estimate structural models, allowing for general equilibrium effects on the labor market. Chapter 1 studies an increase in the level of employment protection in Portugal and Chapter 2 considers the introduction of a minimum working time in France

Spillover effects of employment protection

Estimates of the impact of employment protection heavily rely on reduced-form methods, assuming that there are no indirect effects between firms. This paper exploits a labor law reform implemented in Portugal in 2009 which restricted the use of fixed-term contracts for large firms above a specific size threshold, to investigate and quantify spillover effects. Standard reduced-form estimates based on the hypothesis of the absence of spillover towards firms for which the reform does not apply yield a negative impact on employment of about 1.5%. However, we find evidence of significant spillovers. The estimation of the macroeconomic effects of the reform with a search and matching model accounting for spillovers yields an almost negligible employment impact of the reform, more than ten times smaller than that obtained with the reduced form estimates. This result underlines that the numerous reduced-formestimates of the impact of employment protection that rely on firmsize thresholds must be interpreted with caution.info:eu-repo/semantics/submittedVersio

Children's Attention-Deficit/Hyperactivity Disorder Symptoms Predict Lower Diet Quality but Not Vice Versa:Results from Bidirectional Analyses in a Population-Based Cohort

BACKGROUND: As an adjuvant for medication, dietary changes focused on specific nutrients have been proposed to prevent or reduce attention-deficit/hyperactivity disorder (ADHD) symptoms. However, whether an overall healthy dietary pattern is associated with ADHD symptom severity during childhood remains unclear. Furthermore, it is not clear what the direction of this association is. OBJECTIVES: We aimed to examine the association between dietary patterns and ADHD symptoms in school-aged children. In addition, we aimed to identify the temporal direction of this association-that is, whether dietary patterns predict ADHD symptoms or vice versa. METHODS: We analyzed data from 3680 children participating in the Generation R Study, a prospective cohort in Rotterdam, Netherlands. ADHD symptoms were assessed with parent-report questionnaires at ages 6 and 10 y using the Child Behavior Checklist. Dietary intake was assessed at the age of 8 y with a validated food-frequency questionnaire. We computed a diet quality score reflecting adherence to dietary guidelines. We examined bidirectional associations of diet quality with ADHD symptom scores using multivariable linear regression analysis and cross-lagged modeling. RESULTS: Linear regressions showed that more ADHD symptoms at age 6 y were associated with a lower diet quality score at age 8 y (SD score = -0.08; 95% CI: -0.11, -0.05) but that diet quality at age 8 y was not associated with ADHD symptoms at age 10 y. Cross-lagged models confirmed a unidirectional relation from ADHD symptoms to diet quality but not vice versa. Associations did not differ by overweight status or between boys and girls. CONCLUSION: Our study suggests that children with more ADHD symptoms may be at higher risk of an unhealthy diet but that overall diet quality does not affect ADHD risk

Les effets micro et macro des politiques sur le marché du travail

Cette thèse présente de nouveaux résultats sur les effets des institutions du marché du travail et propose de nouveaux outils afin de les quantifier. De nombreuses régulations de l'emploi sont toujours débattues et il est nécessaire de pouvoir relier les effets de ces régulations sur les travailleurs et entreprises à leur impact agrégé. Ces travaux évaluent les effets des réformes sur le marché du travail au niveau microéconomique (sur les travailleurs et entreprises) et au niveau macroéconomique (sur l'emploi, le chômage et le bien-être). Les effets de débordement ou d'équilibre général, ainsi que l'hétérogénéité sont pris en compte afin de connecter les deux aspects. A partir de données administratives sur les travailleurs et les entreprises et de méthodes d'évaluation en forme réduite, je documente les effets des politiques sur le marché du travail sur les individus et entreprises directement visés, mais aussi les effets indirects. Ensuite, afin de quantifier les effets agrégés en tenant compte des effets directs et indirects, je construis et estime des modèles structurels qui modélisent les effets d'équilibre général sur le marché du travail.Le Chapitre 1 porte sur une augmentation du niveau de protection de l'emploi au Portugal et le Chapitre 2 s'intéresse à la mise en place d'une durée minimale de travail en France.This dissertation documents new evidence on the effects of labor market institutions and provides new tools to assess the impact of labor policies. Many labor market regulations remain controversial, and we lack evidence connecting the impact of these regulations on firms and workers and their aggregate effects. The dissertation evaluates the effects of labor market reforms at the microeconomic level (on workers and firms) and at the aggregate level (on overall employment, welfare, and the unemployment rate). It also accounts for spillovers, general equilibrium effects and heterogeneity to connect the micro and macro impacts. Relying on administrative data on workers and firms and reduced-form evaluation methods, I provide evidence on the effects of labor market policies on targeted individuals and firms, but also on the indirect effects. Second, to quantify the aggregate impact accounting for both direct and indirect effects, I build and estimate structural models, allowing for general equilibrium effects on the labor market.Chapter 1 studies an increase in the level of employment protection in Portugal and Chapter 2 considers the introduction of a minimum working time in France

The Effects of the Legal Minimum Working Time on Workers, Firms and the Labor Market

This paper provides new evidence on how firms and workers adjust to a restriction on lowhour jobs. I exploit a unique reform introducing a minimum workweek of 24 hours in France in 2014, affecting 15% of jobs. Drawing on linked employer-employee data and an event study design, I find a firm-level reduction in the number of jobs and an increase in average hours per worker. Overall, total hours worked in the firm decreased significantly, showing imperfect substitutability between workers and hours. The effects differ by gender: part-time female workers were replaced by full-time male workers. Importantly, reduced-form evidence indicates the reallocation of workers from firms highly exposed to the policy to firms less exposed. To quantify the aggregate impact taking into account these effects, I build and estimate a search and matching model with heterogeneous workers and firms. I find that the minimum workweek destroyed 1% of jobs but had no effect on total hours, due to positive general equilibrium effects. Finally, the gender gap in welfare increased by 3% because women were more affected by the direct negative employment effects and benefited less from reallocation effects

Employment Effects of Restricting Fixed-Term Contracts: Theory and Evidence

This paper examines a labor law reform implemented in Portugal in 2009 which restricted the use of fixed-term contracts to reduce labor market segmentation. The reform targeted establishments created by large firms above a specific size threshold, covering about 15% of total employment. Drawing on linked employer-employee longitudinal data and regression discontinuity methods, we find that, while the reform was successful in reducing the number of fixed-term jobs, it did not increase the number of permanent contracts and decreased employment in large firms. However, we find evidence of positive spillovers to small firms that may bias reduced form estimates. To evaluate general equilibrium effects, we build and estimate a directed search and matching model with endogenous number of establishments and jobs. We find spillover effects that induce small biases on reduced form estimates but that significantly change the evaluation of the overall impact of the reform because they diffuse to the whole economy. We estimate that the reform slightly reduced aggregate employment and had negative effects on the welfare of employees and unemployed workers

Employment Effects of Restricting Fixed-Term Contracts: Theory and Evidence

This paper examines a labor law reform implemented in Portugal in 2009 which restricted the use of fixed-term contracts to reduce labor market segmentation. The reform targeted establishments created by large firms above a specific size threshold, covering about 15% of total employment. Drawing on linked employer-employee longitudinal data and regression discontinuity methods, we find that, while the reform was successful in reducing the number of fixed-term jobs, it did not increase the number of permanent contracts and decreased employment in large firms. However, we find evidence of positive spillovers to small firms that may bias reduced form estimates. To evaluate general equilibrium effects, we build and estimate a directed search and matching model with endogenous number of establishments and jobs. We find spillover effects that induce small biases on reduced form estimates but that significantly change the evaluation of the overall impact of the reform because they diffuse to the whole economy. We estimate that the reform slightly reduced aggregate employment and had negative effects on the welfare of employees and unemployed workers

Spontaneous ecological recovery of vegetation in a red gypsum landfill: Betula pendula dominates after 10 years of inactivity

International audienceRed gypsum is the product of the neutralization of titanium dioxide (TiO 2) extraction residue from ilmenite and anatase. The disposal of red gypsum creates heterogeneous plots with layers that may include Fe, Ca, Al, Mg, Mn, S, and other elements and an alkaline pH that makes revegetation complicated and slow. The vertical and horizontal dispersion of the sediment particles are the main concern. Therefore, the establishment of precise vegetation cover is needed to address this issue. One of the aims of this study was (1) to explore the distribution of the spontaneous vegetation found along a red gypsum-formed landfill located at the Ochsenfeld site in eastern France. Additionally, (2) some pedological parameters were also studied to determine the most significant red gypsum chemical drivers influencing the occurrence and abundance of the vegetation within the site. The Braun-Blanquet scale was used to rate the species presence in the field contained in the spontaneous vegetation dataset. The vegetation survey revealed the presence of 59 species from 23 families. The most abundant species was Betula pendula, and a further cluster analysis enabled the differentiation of areas with this species. The CaCl 2 extractable concentrations of the nutrients and trace elements, as well as the pH and the organic matter (OM) present in the sampled substrate, were used to form the pedological parameters dataset. A multiple factor analysis (MFA) was performed to link the large datasets together and revealed 3 groups of plants. Group 1 was composed of pH-tolerant species such as B. pendula and S. caprea. Group 2 was formed by Cr-Zn-tolerant species, including Echium vulgare and R. pseudoacacia. Finally, group 3 was characterized by species such as Clematis vitalba and Artemisia vulgaris that tolerate the presence of Na. The MFA revealed a correlation between the Betula pendula distribution and the pH, CaCl 2 extractable P concentration and organic matter. On the other hand, A lack of relation of the CaCl 2 extractable concentrations of Fe, Mn, Na, Si and K were also found. This study aided in the selection of an adapted candidate for the implementation of the revegetation strategy of a red gypsum landfill in eastern France. Further tests were performed at the site using white birch for Mn accumulation and topsoil stabilization in situ