La thèse explore l'opportunité d'utiliser des micro-données, sous la forme de données individuelles de firmes, pour dépasser les limites imposées par les données spatialement agrégées généralement utilisées en géographie économique. Le cas d'étude est l'estimation des exportations régionales, y compris les exportations vers d'autres régions du même pays. Prenant la Belgique comme exemple, la thèse présente un nouveau modèle d'estimation de ces exportations qui intègre un modèle gravitaire d'estimation des flux entre lieux de production et lieux de consommation avec les informations contenues dans les tables d'entrée-sortie à l'échelle nationale. Les résultats du modèle confirment l'hypothèse de départ sur l'importance de la consommation locale ou à courte distance du lieu de production.Ces résultats sont analysés devant l'arrière-fond des débats passés et actuels en géographie économique et en politique de développement régional en Europe. Un regard critique est posé sur la notion des politiques « place-based », généralement focalisées sur des politiques de l'offre. Avec le soutien des estimations sortant du modèle l'argument est avancé que la demande locale joue un rôle important pour les économies régionales. Cet argument est renforcé par une revue des débats concernant l'importance de la distance géographique dans les relations économiques.La thèse met également un grand accent sur les questions de méthodes et de données. Elle présente en détail les difficultés liées à l'utilisation de données individuelles, notamment le problème du géocodage. L'utilisation de système d'information géographiques existants dans la construction du modèle est montré, argumentant que de tels systèmes facilitent la vie aux chercheurs en géographie économique dès lors qu'ils utilisent des données massives positionnées dans l'espace réel. L'utilisation de telles données est aussi analysée dans le contexte de la naissance du mouvement du « Big Data » qui pose des questions sur les paradigmes actuels et futurs de la recherche en géographie économique. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Doctorat en philosophie et lettres / info:eu-repo/semantics/nonPublished

Les travaux présentés dans ce manuscrit traitent de la détermination de classes de systèmes selon leur mode de vieillissement dans l'objectif de prévenir une défaillance et de prendre une décision de maintenance. L’évolution du niveau de dégradation observée sur un système peut être modélisée par un processus stochastique paramétré. Un modèle usuellement utilisé est le processus Gamma. On s’intéresse au cas où tous les systèmes ne vieillissent pas identiquement et le mode de vieillissement est dépendant du contexte d’utilisation des systèmes ou des propriétés des systèmes, appelé ensemble de covariables. Il s’agit alors de regrouper les systèmes vieillissant de façon analogue en tenant compte de la covariable et d’identifier les paramètres du modèle associé à chacune des classes.Dans un premier temps la problématique est explicitée avec notamment la définition des contraintes: incréments d’instants d’observation irréguliers, nombre quelconque d’observations par chemin décrivant une évolution, prise en compte de la covariable. Ensuite des méthodes sont proposées. Elles combinent un critère de vraisemblance dans l’espace des incréments de mesure du niveau de dégradation, et un critère de cohérence dans l’espace de la covariable. Une technique de normalisation est introduite afin de contrôler l’importance de chacun de ces critères. Des études expérimentales sont effectuées pour illustrer l'efficacité des méthodes proposées / The work presented in this thesis deals with the problem of determination of classes of systems according to their aging mode in the aim of preventing a failure and making a decision of maintenance. The evolution of the observed deterioration levels of a system can be modeled by a parameterized stochastic process. A commonly used model is the Gamma process. We are interested in the case where all the systems do not age identically and the aging mode depends on the condition of usage of systems or system properties, called the set of covariates. Then, we aims to group the systems that age similarly by taking into account the covariate and to identify the parameters of the model associated with each class.At first, the problem is presented especially with the definition of constraints: time increments of irregular observations, any number of observations per path which describes an evolution, consideration of the covariate. Then the methods are proposed. They combine a likelihood criterion in the space of the increments of deterioration levels, and a coherence criterion in the space of the covariate. A normalization technique is introduced to control the importance of each of these two criteria. Experimental studies are performed to illustrate the effectiveness of the proposed methods

Cette thèse concerne les systèmes de surveillance des turboréacteurs. Le développement de tels systèmes nécessite une phase d’évaluation et d’optimisation des performances, préalablement à la mise en exploitation. Le travail a porté sur cette phase, et plus précisément sur les performances des fonctions de détection et de pronostic de deux systèmes. Des indicateurs de performances associés à chacune de ces fonctions ainsi que leur estimation ont été définis. Les systèmes surveillés sont d’une part la séquence de démarrage pour la fonction de détection et d’autre part la consommation d’huile pour la fonction de pronostic. Les données utilisées venant de vols en exploitation sans dégradations, des simulations ont été nécessaires pour l’évaluation des performances. L’optimisation des performances de détection a été obtenue par réglage du seuil sur la statistique de décision en tenant compte des exigences des compagnies aériennes exprimées en termes de taux de bonne détection et de taux d’alarme fausse. Deux approches ont été considérées et leurs performances ont été comparées pour leurs meilleures configurations. Les performances de pronostic de surconsommations d’huile, simulées à l’aide de processus Gamma, ont été évaluées en fonction de la pertinence de la décision de maintenance induite par le pronostic. Cette thèse a permis de quantifier et d’améliorer les performances des fonctions considérées pour répondre aux exigences. D’autres améliorations possibles sont proposées comme perspectives pour conclure ce mémoire / This thesis deals with monitoring systems of turbojet engines. The development of such systems requires a performance evaluation and optimization phase prior to their introduction in operation. The work has been focused on this phase, and more specifically on the performance of the detection and the prognostic functions of two systems. Performances metrics related to each of these functions as well as their estimate have been defined. The monitored systems are, on the one hand, the start sequence for the detection function and on the other hand, the oil consumption for the prognostic function. The used data come from flights in operation without degradation, simulations of degradation were necessary for the performance assessment. Optimization of detection performance was obtained by tuning a threshold on the decision statistics taking into account the airlines requirements in terms of good detection rate and false alarm rate. Two approaches have been considered and their performances have been compared for their best configurations. Prognostic performances of over oil consumption, simulated using Gamma processes, have been assessed on the basis of the relevance of maintenance decision induced by the prognostic. This thesis has allowed quantifying and improving the performance of the two considered functions to meet the airlines requirements. Other possible improvements are proposed as prospects to conclude this thesis

La description des propriétésspectrales des plasmas hautement ionisés –comme ceux rencontrés en fusion nucléaire,en astrophysique et en expérimentationlaser-plasmas –peut nécessiter différentstypes d’interprétation, parmi lesquelsl’approche détaillée ou raie-par-raieimpliquant de la diagonalisation del’Hamiltonien du système et, l’approchestatistique basée sur la caractérisation desstructures spectrales à travers les momentsde distribution.Ce travail de thèse a pour objectif d'étudier etde mettre en œuvre les méthodes statistiquestraitant des cas où de nombreuses raies seregroupent en faisceaux de transition nonrésolus (UTA pour Unresolved TransitionArray).Pour cela, des études analytique et numériqueont été menées. D’une part, les momentsd’ordre élevé de la distribution d’énergies spinorbiteont été obtenus, en utilisant lestechniques de calcul de moyennes qui fontintervenir les résultats de la secondequantification et de l’algèbre de momentangulaire. D’autre part, après avoir implémentéun programme de post-traitement des donnéesatomiques produites par le code FAC (FlexibleAtomic Code), en mode détaillée comme enmode UTA, les spectres d’émission et / The description of spectralproperties of highly ionized plasmas – asthose studied in stellar atmospheres, facilitiesfor nuclear fusion, or laser-plasmasexperiments – may require different types ofinterpretation, among which the detailed line by-line accounting which relies on Hamiltoniandiagonalization and the statistical approachbased on the characterization of spectralstructures through distribution moments.My PhD work aims at developing statisticalmethods dealing with situations whereabundant lines gather in Unresolved TransitionArrays (UTA).To this end, analytical and numerical analysishave been carried out. On one hand, high-ordermoments of spin-orbit energy have beenderived using averaging calculation techniquesbased on second quantization results andangular momentum algebra. On the other hand,after implementing a post-processing programfor both detailed and UTA computations of theFlexible Atomic Code (FAC), emission andabsorption spectra of tungsten plasmas havebeen studied in tokamak-equivalentthermodynamic conditions.Results of this thesis should hopefully stimulatefurther analysis on averages computationinvolving complex transition processes.

The main idea of this thesis is to study three different issues, economic, political, or financial, related to three different public infrastructure sectors, transport, water and sewerage, and electricity, by using three different methodological approaches. In the first chapter, I make creative use of a non-parametric technique traditionally used to measure the relative efficiency of a set of similar firms, data envelopment analysis, to identify the most likely objective, economic vs. political, behind a specific policy. In the second chapter I empirically investigate the effects of the increasing private financial ownership of the water and sewerage utilities in England and Wales on key outcome variables such as leverage levels and consumer bills. Finally, in the third chapter, I evaluate an equity-aimed policy introduced in the electricity sector in Spain in 2009 by measuring the effect of its introduction on the probability of a household of being energy poor.Chapter One – Unbundling political and economic rationality: a non-parametric approach tested on transport infrastructure in SpainThis paper suggests a simple quantitative method to assess the extent to which public investment decisions are dominated by political or economic motivations. The true motivation can be identified by modeling each policy goal as the focus of the optimization anchoring a data envelopment analysis of the efficiency of the observed implementation. In other words, we rank performance based on how far observed behavior is under each possible goal, and the goal for which the distance is smaller reveals the specific motivation of the investment or any policy decision for that matter. Traditionally, data envelopment analysis is used to measure the relative efficiency of a set of firms having a similar productive structure. In this case, each firm corresponds to a different policy year, the policy being the determinant of the investment made.The approach is tested on Spain’s land transport infrastructure policy since it is argued by many observers to be driven more by political than economic concerns, resulting in a mismatch between capacity investment and traffic demand. History has shown that when the source of financing has been private, the network has been developed in areas with high demand, i.e. the Northern and Mediterranean corridors. When the source has been public, the network has been developed following a radial pattern, converging from a to Madrid. The method clearly shows that public investments in land transport infrastructure have generally been more consistent with a political objective – the centralization of economic power – than with an economic objective – maximizing mobility –.Chapter Two – On the effects of the private financial ownership of regulated utilities: lessons from the UK water sectorThis paper analyzes the quantitative impact of the growing role of non-traditional financial actors in the financing structure and consumer pricing of regulated private utilities. The focus is on the water sector in England and Wales, where the effect of the firms’ corporate financing and ownership strategies on key outcome variables may have been underestimated. The sector was privatized in 1989, year in which the 10 regional monopolies became 10 water and sewerage companies, listed and publicly traded on UK Stock Exchanges. Since then, six of the ten have been de-listed, bought-out by private equity – investment and infrastructure funds. I make use of this variation in ownership to measure the effect on leverage levels and consumer bills.I develop a theoretical framework allowing me to derive two hypotheses: first, the buyout of a company increases its leverage level, and second, the buyout of a company increases the consumer bill through higher leverage levels. The empirical analysis is based on two sequential steps: a staggered difference-in-differences estimation shows that private equity buyouts increase the leverage levels of water utilities. An instrumental variable and two-stage least squares estimation then show that these higher leverage levels increase the average consumer bills of bought-out utilities more than if they had not been bought-out. The estimated impact of the private equity buyouts in the sector in England and Wales on the annual average consumer bill ranges from 13.5 to 32.6 GBP, for a sample average bill of about 427 GBP.Chapter Three – Understanding the effectiveness of the electricity social rate in reducing energy poverty in SpainThis paper analyzes the causal impact of the introduction of a social subsidy, the bono social de electricidad, in Spain's electricity market in 2009. The measure was introduced following the surge in energy poverty, increasing particularly after the financial crisis. Using data from the family budget survey from 2006 to 2017, we evaluate the social policy in its fight against energy poverty.We proceed in two steps. First, we use a difference-in-differences approach to measure such a causal impact and to analyze how the introduction of the measure directly affected eligible households. We find that the introduction of the subsidy has reduced the likelihood of energy poverty for the eligible households. Therefore, the bono social de electricidad has reached its equity objective of increasing affordability of electricity. The second step aims at understanding how specifically the introduction of the subsidy affects consumers. We find that, in reaction to lower effective prices, households do not increase their consumption of electricity, resulting in lower total electricity expenditure. We are therefore able to show that this policy did not induce a change in the consumption behavior and that the increased affordability entirely resulted in a decrease of expenditure in electricity / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

Using public support as the baseline, the aim of the Ph.D. thesis is firstly to assess its effectiveness in alleviating firms’ financing constraints (Chapter 2) and in enhancing the innovation-growth linkage (Chapter 5), in comparison with other financing sources. Secondly, the research undertaken also explores public policy effectiveness in two periods of time: ex-ante and ex-post analysis. In the former, effectiveness is assessed according to whether the characteristics of the project selected for the subsidy are in line with the policy targets (Chapter 3). In turn, the ex-post analysis assesses firms’ effectiveness in achieving the planned goal and the sustainability of the achieved outcomes (Chapter 4). Chapter 2 provides evidence that, in addition to a guarantee for loans, measures to facilitate equity investments and making existing public measures easier to obtain could be considered as the main solutions for future financing. Tax incentives for financially constrained firms are revealed to be the least important factor. Chapter 3 aims to understand which kinds of projects are selected for an innovation subsidy and if the characteristics of the project selected are in line with the policy target. The results show the selection process seems to be particularly effective in meeting the goals as regards the amount of investment, as well as the expected effect on enhanced internationalization and productivity. Nevertheless, the study also reveals some failures in the selection process, namely in terms of the intensity of the project’s contribution to growth. Chapter 4 assess firm performance after project implementation. Results show that subsidized firms reached targets linked with employment level and sales more easily than labour productivity and value creation. Chapter 5 reveals that equity financing has a greater effect on the strategic decision to innovate and the highest output additionality on firm turnover growth. Grants have a more moderate effect on innovation and firm growth (both turnover and employment). / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

In the past decades, decentralization has become increasingly important in both developing and developed countries. Based on the standard decentralization theorem, policy makers believe that local governments are closer to citizens and know more about local contexts and needs than the national governments. Consequently, they can design policies leading to a more efficient allocation of public goods. Moreover, when accompanied by empowerment of local decision-makers, decentralization is supposed to make local politicians more accountable to voters in a way that national politicians are not. Yet, the effective implementation of decentralization policies may heavily rely on local institutions. This thesis contributes to a rising literature analyzing the political economics of decentralization, that is the extent to which local political dynamics may reinforce or jeopardies decentralization reforms, ultimately affecting the citizens' well-being. I consider three countries that have devolved power to local politicians to a different extent, and tackle three obstacles that may undermine the beneficial effects of decentralization reforms: first, strong political competition at the local level; second, the need for coordinating the provision of a local public good; the interaction between political competition and coordination needs on accountability and eventually the quality of a local public good. Political competition may hinder the beneficial effects of decentralization on stability in a post-war country like Burundi. After a long-lasting and devastating civil war, in 2010 Burundi organized the first local elections, with the hope of establishing political stability through democratic means. However, together with two co-authors, I show that such political decentralization partly failed. We use a unique dataset and geographic fixed effects to show that violence was higher in municipalities characterized by fierce political competition and acute polarization between demobilized rebel groups. The former protagonists of the civil war used the elections as another stage to engage in a stiff struggle for power, and used “specialists of violence” to illicitly steer the electoral outcome.Political dynamics may undermine the coordinated management of the local sewerage networks in Brazil. I use geospatial data to proxy for the scope of coordination between neighboring municipalities: municipalities that are close “enough” are those more exposed to the spreading of water-borne diseases, which ultimately justifies cross-boundary coordination of local sanitation networks. By exploiting a Regression Discontinuity Design in close municipal elections, I show that political alignment between neighboring mayors may lead to lower access to sanitation networks of households. I argue that mayors co-managing a public good have a stronger incentive to monitor each other and ensure effective coordination when they come from different political parties, essentially because of political competition. Mayors from the same party would tend instead to be more lenient to each other, ultimately undermining the quality of the local public good co-provided.Finally, I study the effect of decentralization on the accountability of local politicians co-managing local police in Belgium. In 2005, one of the regions of Belgium introduced the direct election of mayors, while in the rest of the country mayors remained appointed by the local city councils. Together with a co-author, I exploit this reform to show that crime incidence in municipalities affected by the reform decreased faster than anywhere else in the country. We argue that the direct election of mayors increase the accountability of mayors and their incentives to fight criminality. However, we find that the effects of the reform decrease when an increasingly larger number of neighboring mayors has to coordinate the local police. The need to coordinate the local police blur accountability, mitigating the effects of the reform. To conclude, the overarching message of the thesis is that local institutions matter for the implementation of decentralization policies. Policy-makers redesigning the distribution of power between levels of government need to take into account pre-existing political and institutional dynamics that could jeopardize their policy initiatives. In particular, policy-makers could envision decentralization “at different speeds”, enabling local actors to identify objectives of development together with the right tools to pursue them, and finally decentralize accordingly. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

The thesis contains four essays, covering topics in the field of real-time macroeconometrics, forecasting and applied macroeconomics. In the first two chapters, I use recent techniques developed in the "nowcasting" literature in order to analyse and interpret the macroeconomic news flow. I use them either to assess current macroeconomic conditions, showing the importance of foreign indicators dealing with small open economies, or linking macroeconomic news to asset prices, through a model that help us interpret macroeconomic data and explaining the linkages between macro variables and financial indicators. In the third chapter, I analyse the link between macroeconomic data in real-time and the yield curve of interest rates, constructing a forecasting model which takes into account the peculiar characteristics of the macroeconomic data flow. In the last chapter, I present a Bayesian Vector Autoregression model built in order to analyse the last two crisis in the Eurozone (2008-09, and 2011-12) identifying their unique characteristics with respect to historical regularities, an issue of great importance from a policy perspective. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

Les espèces végétales exotiques peuvent devenir envahissantes une fois naturalisées sur un nouveau territoire. La méthode de lutte la plus efficace étant la prévention, il est primordial de pouvoir prédire à l'avance si une nouvelle espèce introduite deviendra envahissante. Afin d'en arriver à un outil d'aide à la décision facile d'utilisation, il importe de développer des modèles plus simples, ayant peut-être un pouvoir explicatif moins grand, mais qui seront par contre plus faciles à comprendre et à utiliser. Il est possible de simplifier un modèle en utilisant moins de variables mais en les choisissant mieux, sur une base théorique. Le but de ce mémoire est donc de tester la force de la relation liant l'aire de répartition d'origine eurasiatique avec l'abondance et l'étendue de l'aire de répartition d'introduction en Amérique du Nord. La variable explicative principale, l'aire de répartition d'origine eurasiatique, a été utilisée avec deux autres covariables, soit le temps de résidence sur le continent nord-américain et le cycle de vie des espèces afin de bâtir un modèle statistique. Ce dernier a été testé à deux échelles géographiques, soit à l'échelle d'un pays entier, les États-Unis, et à une échelle plus régionale. L'utilisation de spécimens d'herbier et d'autres sources de données disponibles en ligne a permis de construire une base de données comportant un grand nombre d'espèces (N = 481). Les modèles ont révélé qu'avec peu de variables explicatives, il est possible d'expliquer une proportion importante du phénomène d'envahissement et d'abondance (> 40 %) dans certaines régions des États-Unis. Cette recherche contribue au développement d'un outil d'aide à la décision simple et démontre qu'il est possible d'expliquer une partie importante le phénomène d'abondance et d'étendue des espèces exotiques grâce à des données disponibles et à un petit nombre de variables bien sélectionnées.