[pt] O objeto desta dissertação é investigar o impacto do câmbio em diversos setores de exportação no Brasil, utilizando equações econométricas uniequacionais. Em particular, é utilizado o modelo em defasagens autoregressivas distribuídas (ADL) para obtenção das elasticidades de longo prazo. A dinâmica de curto prazo é obtida sob a forma de um modelo de correção de erros (ECM). São estimadas seis formas alternativas para a equação das exportações, as quais se diferenciam pelas medidas de câmbio (três) e renda mundial (duas) utilizadas. As estimativas das elasticidades- câmbio das exportações indicam uma relação de longo prazo na maior parte dos 18 setores estudados, porém seu impacto sobre o nível das exportações não é considerado alto, pois as estimativas em sua maioria são inferiores a unidade. No curto prazo, o impacto do câmbio revelou-se ainda mais baixo. Em síntese, o presente estudo mostra que, para o crescimento das exportações, o comportamento do câmbio não é o fator de destaque. No bojo desse estudo, no entanto, outros determinantes das exportações setoriais são identificados: renda mundial, competitividade externa e o produto potencial da indústria. / [en] The aim of this dissertation is to investigate the impact of the exchange rate in several export sectors of the brazilian economy, throughout the use of uniequation econometric models. In particular, we make use of the autoregressive distributed lags model (ADL) to obtain the long run exchange rate elasticities. The short run dynamics is obtained by use of a model with error correction mechanism (ECM). We estimate six alternative forms for the export equations, which differ by the indicators of exchange rate (three) and world income (two) used. The elasticities estimated for the majority of the 18 export sectors investigated suggest the existence of a long run relation between exchange rate and quantum of exports. Nevertheless this impact is not substantial, given the small size of the elasticities coefficients. On the short run, the exchange rate impact was even less pronounced. In a nut shell, our study shows that, in Brazil, the growth of exports is not very much affected by the exchange rate, although other factors have been found to have an effect: world income, foreign competition and industry potential product.

No description available.

Une des particularités du marché des compagnies aériennes est la grande divergence des prix des billets pour les mêmes vol. Cela reflète principalement l'incapacité des entreprises à modifier facilement les volumes de production et/ou à les stocker. Le développement et l'utilisation des modèles de "yield management" (modèles d'attribution des sièges) ont été centrés sur les compagnies aériennes proposant différents types de tarifs pour un même vol. L'objectif de cette thèse est de construire un certain nombre de modèles économiques pour expliquer la dispersion des prix sur le marché du transport aérien à partir de différents points de vue. Dans le chapitre 3, je crée un modèle de prix direct qui explique comment différentes caractéristiques du produit et du consommateur influencent le niveau de prix. Le chapitre 4 est consacré aux différences de niveau de prix du point de vue de la concurrence. Dans un jeu stratégique où les entreprises se font concurrence, ! 'ensemble de stratégies rationalisables pour chaque joueur implique toutes les meilleures réponses aux décisions des autres. Ce chapitre propose un test empirique de l'existence de l'équilibre de Nash unique dans un oligopole de Cournot. Dans le chapitre 5, je traite le marché des passagers aériens comme un marché différenciant les produits et applique un modèle logit multinomial pour calculer les élasticités-prix. Le modèle logit (mettant particulièrement l'accent sur l'hétérogénéité des consommateurs) estime de quelle manière les différentes caractéristiques du produit influencent les parts de marché. / Nowadays one of peculiarities of the liberalized airline market is a huge divergence of ticket prices for the same flights. Mostly it reflects the companies' being unable to easily change the volumes of production or/and store them. The development and use of the yield management models (seat allocation models) have centered on airlines offering a variety of different types of fares for travel on the same flight. The goal of this dissertation is to construct a number of economic models to explain the price dispersion on the airline market from the different points of view. In Part 3, I create a direct price mode! which explains how different product and consumer characteristics influence the price level. It is shown how different attributes like the moment of ticket reservation, ticket class, weekday of the departure and number of coupons define the price and how it corresponds to the consumer characteristics (gender, income, age, etc.). Part 4 is devoted to the differences of the price level from the competition point of view. In a strategic game where firms compete against each other the set of rationalizable strategies for each player entails ail the best responses to the others' decisions. This chapter proposes an empirical test of the existence of the unique Nash equilibrium in a Cournot oligopoly. In Part 5 I treat an airline passenger market as a market with the product differentiation and apply a multinomial logit model to calculate price elasticities. The logit model (with a special focus on the consumers heterogeneity) estimates how the different product characteristics influence the market shares.

The United States cheese consumption has grown considerably over the years. Using Nielsen Homescan panel data for calendar years 2005 and 2006, this dissertation examines the effect of economic and socio-demographic factors on the demand for disaggregated cheese varieties and on the cheese industry in general. In the first essay, we estimated the censored demand for 14 cheese varieties and identified the respective own-price and cross-price elasticities. Also, non-price factors were determined affecting the purchase of each variety as well as the impact of generic dairy advertising. Results revealed that most of the natural cheese varieties have an elastic demand while the processed cheese products exhibited inelastic demands. Strong substitution and complementarity relationships were identified as well, and a two quarter carry-over effect of advertising was observed for most of cheese demands. Results also showed that household demographics affected the demands differently, depending on the nature of the cheese varieties. The second essay examined the impact of retail promotion on the decision to purchase private label processed cheese products using a probit model. A strong negative relationship was found between national brand manufacturer couponing activity and the private label purchase decision. Therefore, national brand couponing appears to be an effective strategy for manufacturers to deter private label growth. This analysis also shows that the decision of purchasing a private label cheese product is influenced by socio-demographic characteristics of the household, namely household income and size, age and education level of the household head, race, ethnicity, and location. In the third study, the feasibility of fortifying processed cheese with omega-3 is investigated. This ex-ante analysis took into account the market conditions and evaluates the increase in the demand for processed cheese needed to offset the costs of fortification in order to maintain the profitability of manufacturers like Kraft. Initially, the censored demand for processed cheese products is estimated using panel data; subsequently, the profitability of manufacturing such product is determined.This analysis shows that, within reasonable market conditions and reasonable marginal costs, the fortification of processed cheese products with omega-3 fatty acids indeed is feasible from a profitability standpoint to manufacturers.

This dissertation contributes to the literature and current discussions on the European postal markets and the universal service obligations (USO). It consists of three independent chapters.<p><p>In chapter one, we investigate the consumers' preferences for various kinds of postal services. As such, we begin by reviewing the market and regulatory conditions for Europe and for our case study, Belgium. Then using data provided by the incumbent provider, the Belgian post (Bpost), we estimate demand price elasticities. The data comprises customer transactional information on letter mail, direct mail, parcels & express services, press delivery and value added services for the 2008-2009 period. These categories constitute not only the important lines of services that Bpost offers to its clients but also the main segments that constitute the whole Belgian postal market. As such, and using standard methods, we estimate for each service an equation that explains demand by prices, product varieties (i.e. mixes or combinations of volume, weight, priority and destination, inter alia), income, regulation proxies and other socioeconomic variables. The estimated price elasticities for regulated and partially regulated services are around -1.1, whereas for unregulated segments they fluctuate between -2.1 and -2.8. The lowest price elasticity is obtained for direct mail services (-1.0); the highest ones are associated with value added services (-2.1) and registered mail (-3.3). Price elasticities may be influenced by the cyclical effects during the period of analysis. Therefore, elasticities are higher when compared with the empirical evidence obtained for other countries and through the various methodologies applied over the last decades. The fact that technological substitutes, such as expenditures on telephony and internet access for daily and administrative mail services and, radio and television advertising for direct mail services, could not be accounted for (because there were no data available) may however be considered as a major limitation for the scope of our results. <p><p>In the second chapter, we explore theoretically the effects of the USO on unregulated markets. In particular, we are interested in investigating its welfare effects when the provision of services cannot be technologically separated. We present a model in which there is an incumbent who provides two services: a universal service and a non-USO service, the latter opened to competition. This is the case of letter mail and direct (or bulk) mail, services which have quite different purposes and regulatory frameworks (i.e. the former is fully regulated whereas the latter is liberalized under the current European Internal Market framework), but are jointly produce at some stages of the postal value chain. The USO is simplified to two dimensions, affordability and quality, implemented as a price cap and a minimum quality standard (MQS) for the provision of letter mail services. The latter involves the technological aspects that we are interested in. We find that the definition of the USO plays an important role in organizing markets that are open to competition. When it imposes few quality requirements (low MQS), the incumbent is not cost efficient enough to provide the high-quality variant of bulk mail, allowing its competitors to cream-skim the segment. However, because there are cost economies, the firm's participation in the segment yields a higher average quality of mail services at lower prices. When the USO is too comprehensive (high MQS), the incumbent exhibits large cost economies that ensure a dominant position in the provision of bulk mail services. Consumers are worse off as competition induces too much service differentiation in order to make profitable the provision. Relaxing the definition of the USO mitigates the competitive advantage of the USP and so, yields improvements in welfare. In the absence of access costs, firms will find profitable to participate in the bulk mail segment. However, foreclosure happens if the USO induces the incumbent to exhibit significant fixed costs. Therefore, the USP may end up as the sole supplier of bulk mail services if the definition of the USO imposes too many quality requirements (high MQS). In that case, the authority must balance the welfare gains of defining USO with the welfare losses of the consumers of the contested service. <p><p>Finally, in the third chapter we consider the ownership aspect of the provision of universal services as an incentive to introduce competition. One can further segment the provision between services for customers located in high-cost areas and services for customers located in low-cost areas. Additionally, under the current EU legislation, the supply is divided between upstream activities (e.g. collection and sorting) and downstream activities (i.e. delivery). The provision of upstream activities in high-cost areas remains in hands of the incumbent firm or the owner of the downstream (delivery) network. The upstream provision in low-cost areas is open to competition, but a retailer may be vertically integrated/separated or legally unbundled with the downstream firm. Legal unbundling means, in our model, that the downstream firm and one upstream firm located in the low-cost area belong legally to the same entity entitled to all profits, whom does not have full control rights over the firms' decisions. That is to say, upstream activities and the downstream services will be managed separately under the same ownership. In this framework we analyze the firm's boundaries in terms of competition development and welfare. We implement two criteria to answer questions like, does vertical separation promotes competition (entry of firms) while covers a larger demand than vertical integration? Does vertical integration demand less public funds to cover demand? Does legal unbundling is worse than ownership separation to promote competition? The first criterion is the probability of entry (of the potential upstream firm), which we determine for each modes of ownership. The second criterion is the cost of public funds. It is implemented by defining a loss function as the difference between the expected consumer surplus when the downstream firm chooses an access fee that maximizes its profits and the consumer surplus when access is priced at marginal cost. The use of both criteria let us conclude that efficient entry occurs when the downstream firm is vertically separated or legally unbundled of the retailer providing services in the low-cost area. However, it is under legal unbundling that the access charge takes its lowest value. The highest cost of public transfers is obtained when firms are vertically separated, but the lowest one is attained when firms are legally unbundled. Therefore legal unbundling constitutes the preferred organizational form to induce competition and to reduce the cost of public funds. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

L’automobile occupe une place fondamentale dans notre société, au point qu’on a pu parler de « civilisation de l’automobile ». En dépit des critiques qui lui sont régulièrement adressées, celle-ci n’a cessé de se renforcer, avec toujours davantage de voitures par adulte et une proportion croissante de déplacements effectués en voiture. Cependant, depuis le tournant du millénaire, on assiste à un retournement de tendance. Pour la première fois, la mobilité en voiture baisse dans les grandes agglomérations, tandis que la circulation automobile plafonne à l’échelle nationale. Cette évolution, du reste, n’est pas spécifique à la France mais s’observe dans l’ensemble des pays développés, une tendance parfois désignée sous le terme de « peak car (travel) ». Parmi les explications les plus convaincantes de ce retournement, figurent l’augmentation du prix du carburant, suivie de la récession de 2008. La volonté des ménages de maîtriser leurs budgets-temps de transport y contribue également, dans un contexte d’allongement des déplacements vers le travail et de dégradation des vitesses de déplacements. En outre, la diffusion de l’automobile se rapproche de la saturation. Si à long terme, la croissance du kilométrage moyen par adulte est indexée sur le taux de motorisation, cependant à moyen terme l’utilisation des véhicules fluctue en fonction du pouvoir d’achat énergétique, et un modèle basé sur ces deux variables suggère qu’on observerait une réaction normale à une augmentation exceptionnelle du prix du carburant. Les facteurs de croissance du taux de motorisation tiennent eux-mêmes principalement à la succession de générations de plus en plus motorisées, surtout chez les femmes, compte tenu d’un accès de plus en plus large au permis de conduire, à l’activité professionnelle, et d’une urbanisation de plus en plus diffuse, qui ont augmenté le besoin d’une seconde voiture. Pour modéliser l’auto-mobilité, on propose une approche emboîtée, individuelle et longitudinale, segmentée en fonction du genre. L’auto-mobilité peut en effet être vue au niveau individuel comme une succession de choix emboîtés, puisque la détention du permis conditionne l’accès à un véhicule personnel, de même que la motorisation conditionne l’usage d’un véhicule. L’avantage d’une approche longitudinale réside dans la possibilité de distinguer entre mesures d’hétérogénéité et de sensibilité, qui ne sont pas équivalentes. Pour chaque niveau de choix, l’approche est structurée autour d’une analyse de type âge-cohorte-période. Globalement, les taux de motorisation sont plus hétérogènes chez les femmes, un résultat qui est susceptible de recevoir une double interprétation, économique ou sociétale. On peut le voir en termes d’inégalités de genre. Mais il peut également s’interpréter comme le reflet d’un statut encore intermédiaire du second véhicule, dont l’opportunité serait davantage évaluée au regard des besoins et des contraintes réels du ménage. A l’inverse, l’usage des véhicules est à la fois plus élevé et plus hétérogène chez les hommes, compte tenu de la fonction collective du véhicule principal et des arbitrages internes aux ménages quant aux choix du lieu de résidence et des lieux de travail des conjoints. Pour finir, on estime à partir de modèles sur données de panel des effets marginaux et des élasticités par rapport au revenu, au prix du carburant et à la densité, qui sont ensuite comparées avec la littérature. Dans l’ensemble, les résultats sont cohérents avec l’analyse descriptive, ainsi qu’avec la littérature. Le modèle permet également de rendre compte du déclin tendanciel des élasticités, traduisant l’approche de la saturation. Pour finir, une évaluation a posteriori confirme l’opportunité d’une modélisation séquentielle, indiquant que les choix de motorisation sont indépendants des niveaux d’usage de la voiture. / Car ownership and use are a decisive part of our society, which was sometimes designed as the “civilization of the car”. Despite many critics, the car has become ever-more central in the modern way of life, with an ever-increasing number of cars per adult and proportion of trips realized by car. However, from the beginning of the millennium, there was a reversal in the trend towards ever-more car use. For the first time, the average number of daily trips realized by car has been falling down in French conurbations, and nationwide traffic by car is leveling off. This situation, nonetheless, is not specific to France but is common to many developed countries, and is often referred to as the “peak car (travel)”. The main explanations for such a downturn include rising fuel prices from the late 1990’s, followed by the recession in 2008, but also household’s willingness to control their travel time budgets, in a context of increasing commuting distances and reduced travel speeds. Besides, the diffusion of car ownership is approaching saturation. While on the long-run, average car travel per adult is indexed on motorization, mid-term fluctuations of average car use per vehicle are related to the energetic purchasing power, and a simple model based on these two variables is suggesting that the stagnation of car use from the 2000’s could be a reaction of a usual kind to an exceptional rise in fuel prices. The growth in motorization is itself principally caused by the follow-up of ever-more motorized generations, especially among women, given their increasing access to driving license, job participation and ever-more diffuse land use patterns, which have increased the need for a second car within households. In order to model auto-mobility, a nested, individual and longitudinal approach is implemented, segmented by gender. Auto-mobility can indeed be seen as a follow-up of nested choices, as driving license is necessary for holding a car, while access to a personal vehicle is itself required for car use. The advantage of a longitudinal approach consists in the ability to distinguish between measures of heterogeneity and sensitivity, which can be shown not to be equivalent. For every given level of choice, the approach is based on an age-cohort-period-type analysis. Motorization rates happen to be more heterogeneous among women, a result which is likely to receive an interpretation either of a social or economic nature. According to the first interpretation, it should be regarded as the illustration of gender inequalities. However, it could also be regarded as reflecting the still-intermediary status of the second vehicle, which opportunity is assessed depending upon household’s specific needs and constraints. On the contrary, car use is at the same time higher and more heterogeneous among men, given the collective function of the first vehicle and household’s internal trade-offs in residential and job choices. Finally, average partial effects and elasticities are estimated from panel data models, either with respect to income, fuel prices or density. Generally, results are consistent with the descriptive part, as with the literature. The model also rationally gives account of the decreasing trend for elasticities, which was often noticed in the literature and reflects the approach of saturation. As a conclusion, an a posteriori evaluation of the assumption of a sequential decision process is made, confirming that choices of motorization and car use are mutually independent.

No description available.

After many decades, macroeconomic effects of fiscal policy have returned to the centre of the economic policy debate. Both automatic fiscal stabilizers and discretionary fiscal stimuli have been used to support aggregate demand during the recent global economic crisis with a subsequent need for large-scale fiscal consolidations. In this context, a proper assessment of the size of automatic fiscal stabilizers and fiscal multipliers represents a key input for fiscal policymaking. This dissertation provides a quantitative analysis of the interactions between fiscal policy and real economy in the Czech Republic. The impact of real economy developments on public finances is assessed based on the methods of the OECD, the European Commission and the ESCB for the identification of general government structural balances, i.e. balances adjusted for effects of the economic cycle and net of one-off and other temporary transactions. I find that the underlying fiscal position, as approximated by the government structural balance, was mostly below the level stabilising the debt-to-GDP ratio since mid-1990s. An indistinct improvement in the structural balance can be identified in the period 2004--2007, which was subsequently reversed by the adverse structural impact of the world economic crisis. At the same time, dynamics of unadjusted fiscal balance was largely determined by one-off transactions in the past. The effects of fiscal policy on real economy are analysed using the structural VAR approach. I find that an increase in government spending has a temporary positive effect on output that peaks after one to two years with a multiplier of around 0.6. Tax multiplier appears to be small and, in contrast to standard Keynesian assumptions, positive. Government spending is supportive to private consumption, contradicting the hypothesis of Ricardian equivalence, but it crowds out private investment in the short run. The results should be interpreted with caution, as the analysis is complicated by rapidly changing economic environment in the period of the economic transition, relatively short available time series and a large number of one-off fiscal transactions.

Cette thèse est organisée en trois chapitres. Les deux premiers proposent une approche régularisée pour l’estimation du modèle de données de panel dynamique : l’estimateur GMM et l’estimateur LIML. Le dernier chapitre de la thèse est une application de la méthode de régularisation à l’estimation des élasticités de l’offre de travail en utilisant des modèles de pseudo-données de panel. Dans un modèle de panel dynamique, le nombre de conditions de moments augmente rapidement avec la dimension temporelle du panel conduisant à une matrice de covariance des instruments de grande dimension. L’inversion d’une telle matrice pour calculer l’estimateur affecte négativement les propriétés de l’estimateur en échantillon fini. Comme solution à ce problème, nous proposons une approche par la régularisation qui consiste à utiliser une inverse généralisée de la matrice de covariance au lieu de son inverse classique. Trois techniques de régularisation sont utilisées : celle des composantes principales, celle de Tikhonov qui est basée sur le Ridge régression (aussi appelée Bayesian shrinkage) et enfin celle de Landweber Fridman qui est une méthode itérative. Toutes ces techniques introduisent un paramètre de régularisation qui est similaire au paramètre de lissage dans les régressions non paramétriques. Les propriétés en echantillon fini de l’estimateur régularisé dépend de ce paramètre qui doit être sélectionné parmis plusieurs valeurs potentielles. Dans le premier chapitre (co-écrit avec Marine Carrasco), nous proposons l’estimateur GMM régularisé du modèle de panel dynamique. Sous l’hypothèse que le nombre d’individus et de périodes du panel tendent vers l’infini, nous montrons que nos estimateurs sont convergents and assymtotiquement normaux. Nous dérivons une méthode empirique de sélection du paramètrede régularisation basée sur une expansion de second ordre du l’erreur quadratique moyenne et nous démontrons l’optimalité de cette procédure de sélection. Les simulations montrent que la régularisation améliore les propriétés de l ’estimateur GMM classique. Comme application empirique, nous avons analysé l’effet du développement financier sur la croissance économique. Dans le deuxième chapitre (co-écrit avec Marine Carrasco), nous nous intéressons à l’estimateur LIML régularisé du modèle de données de panel dynamique. L’estimateur LIML est connu pour avoir de meilleures propriétés en échantillon fini que l’estimateur GMM mais son utilisation devient problématique lorsque la dimension temporelle du panel devient large. Nous dérivons les propriétes assymtotiques de l’estimateur LIML régularisé sous l’hypothèse que le nombre d’individus et de périodes du panel tendent vers l’infini. Une procédure empirique de sélection du paramètre de régularisation est aussi proposée. Les bonnes performances de l’estimateur régularisé par rapport au LIML classique (non régularisé), au GMM classique ainsi que le GMM régularisé sont confirmées par des simulations. Dans le dernier chapitre, je considère l’estimation des élasticités d’offre de travail des hommes canadiens. L’hétérogéneité inobservée ainsi que les erreurs de mesures sur les salaires et les revenus sont connues pour engendrer de l’endogéneité quand on estime les modèles d’offre de travail. Une solution fréquente à ce problème d’endogéneité consiste à régrouper les données sur la base des carastéristiques observables et d’ éffectuer les moindres carrées pondérées sur les moyennes des goupes. Il a été démontré que cet estimateur est équivalent à l’estimateur des variables instrumentales sur les données individuelles avec les indicatrices de groupe comme instruments. Donc, en présence d’un grand nombre de groupe, cet estimateur souffre de biais en échantillon fini similaire à celui de l’estimateur des variables instrumentales quand le nombre d’instruments est élevé. Profitant de cette correspondance entre l’estimateur sur les données groupées et l’estimateur des variables instrumentales sur les données individuelles, nous proposons une approche régularisée à l’estimation du modèle. Cette approche conduit à des élasticités substantiellement différentes de ceux qu’on obtient en utilisant l’estimateur sur données groupées. / This thesis is organized in three chapters. The first two chapters propose a regularization approach to the estimation of two estimators of the dynamic panel data model : the Generalized Method of Moment (GMM) estimator and the Limited Information Maximum Likelihood (LIML) estimator. The last chapter of the thesis is an application of regularization to the estimation of labor supply elasticities using pseudo panel data models. In a dynamic panel data model, the number of moment conditions increases rapidly with the time dimension, resulting in a large dimensional covariance matrix of the instruments. Inverting this large dimensional matrix to compute the estimator leads to poor finite sample properties. To address this issue, we propose a regularization approach to the estimation of such models where a generalized inverse of the covariance matrix of the intruments is used instead of its usual inverse. Three regularization schemes are used : Principal components, Tikhonov which is based on Ridge regression (also called Bayesian shrinkage) and finally Landweber Fridman which is an iterative method. All these methods involve a regularization parameter which is similar to the smoothing parameter in nonparametric regressions. The finite sample properties of the regularized estimator depends on this parameter which needs to be selected between many potential values. In the first chapter (co-authored with Marine Carrasco), we propose the regularized GMM estimator of the dynamic panel data models. Under double asymptotics, we show that our regularized estimators are consistent and asymptotically normal provided that the regularization parameter goes to zero slower than the sample size goes to infinity. We derive a data driven selection of the regularization parameter based on an approximation of the higher-order Mean Square Error and show its optimality. The simulations confirm that regularization improves the properties of the usual GMM estimator. As empirical application, we investigate the effect of financial development on economic growth. In the second chapter (co-authored with Marine Carrasco), we propose the regularized LIML estimator of the dynamic panel data model. The LIML estimator is known to have better small sample properties than the GMM estimator but its implementation becomes problematic when the time dimension of the panel becomes large. We derive the asymptotic properties of the regularized LIML under double asymptotics. A data-driven procedure to select the parameter of regularization is proposed. The good performances of the regularized LIML estimator over the usual (not regularized) LIML estimator, the usual GMM estimator and the regularized GMM estimator are confirmed by the simulations. In the last chapter, I consider the estimation of the labor supply elasticities of Canadian men through a regularization approach. Unobserved heterogeneity and measurement errors on wage and income variables are known to cause endogeneity issues in the estimation of labor supply models. A popular solution to the endogeneity issue is to group data in categories based on observable characteristics and compute the weighted least squares at the group level. This grouping estimator has been proved to be equivalent to instrumental variables (IV) estimator on the individual level data using group dummies as intruments. Hence, in presence of large number of groups, the grouping estimator exhibites a small bias similar to the one of the IV estimator in presence of many instruments. I take advantage of the correspondance between grouping estimators and the IV estimator to propose a regularization approach to the estimation of the model. Using this approach leads to wage elasticities that are substantially different from those obtained through grouping estimators.

[ES] El objetivo 2 para el desarrollo sostenible de la ONU es hambre cero. Concretamente, se trata de poner fin al hambre, lograr la seguridad alimentaria (SA) y la mejora de la nutrición y promover la agricultura sostenible. Hay que destacar que la inseguridad alimentaria no es un problema exclusivo de países en desarrollo, sino que en los países llamados desarrollados parte de la población tiene problemas para garantizar una nutrición adecuada. Por otro lado, si bien hasta la fecha gran parte del debate sobre la SA se ha centrado en aspectos relacionados con la accesibilidad y la producción de alimentos, se observa una tendencia hacia un concepto más integral de la SA que abarca también los cambios ambientales globales. Por esta razón, investigadores, gobiernos y organismos internacionales están proponiendo medidas de diversa índole, enfocadas en garantizar la seguridad alimentaria y nutricional de la población, por un lado, y en contrarrestar los impactos negativos que las actividades de producción y consumo de alimentos tienen sobre el medio ambiente y el cambio climático. En este sentido, el registro de datos relacionados con variables económicas y medioambientales, junto al conocimiento de expertos en estas áreas y el uso de herramientas de estadística aplicada, han contribuido a que, a partir de evidencias objetivas, se formalicen de una forma estructurada y coherente las acciones que pueden modificar el comportamiento social y económico de todos los agentes involucrados. En este contexto, la teoría económica en general, y la teoría del consumidor en particular, a partir del registro y procesado detallado de información estadística relacionada, han hecho posible analizar algunos aspectos de las actitudes, comportamientos y preferencias del consumidor. Dichos aspectos pueden ser utilizados como señales de las posibles reacciones que los consumidores tendrían en su demanda por algunos alimentos ante cambios en variables de mercado que no puede controlar, como los precios, o ante acciones de política pública que también pueden modificar sus decisiones de consumo tales como la aplicación de impuestos y/o subsidios, los cuales finalmente afectarán sus metas alimentarias y nutricionales. Por otro lado, el análisis de ciclo de vida (ACV) ha adquirido una gran fortaleza en términos de evaluación medioambiental. En concreto, el ACV en su variante consecuencial (ACV-C) presenta interés para la valoración de las posibles consecuencias sobre el medioambiente ante cambios exógenos en variables económicas o de política medioambiental. En la literatura relacionada con ACV-C se utilizan las elasticidades para conocer la denominada relación de sustitución entre productos alternativos. En general, una elasticidad es una medida cuantitativa que relaciona el cambio porcentual en términos de cantidades para una variable en particular con el cambio porcentual que tenga cualquier otra variable. De esta manera se pueden modelar los cambios que se presentan a corto y largo plazo en los indicadores medioambientales como consecuencia de cambios en variables como los precios o la cantidad de insumos utilizados en la producción de un bien o servicio. Ante este escenario, el objetivo de esta tesis es proponer nuevas metodologías para evaluar la seguridad alimentaria (SA) y la sostenibilidad ambiental asociada al consumo de alimentos, con el fin de promover una seguridad alimentaria sostenible. Los casos de estudio desarrollados se centrarán en España y se utilizarán herramientas metodológicas que involucren la aplicación de la teoría del consumidor, la perspectiva de ciclo de vida y algunos métodos estadísticos. El alcance del objetivo planteado se ha logrado a partir de cuatro objetivos secundarios, y cada uno de ellos ha quedado reflejado en sendos capítulos de la tesis, de los cuales dos se han concentrado en analizar la seguridad alimentaria y los dos restantes en los aspectos medioambientales. / [CAT] El segon dels Objectius per al Desenvolupament Sostenible de la ONU és fam zero. Concretament, es tracta de posar fi a la fam, aconseguir la seguretat alimentària (SA) i millorar la nutrició i promoure la agricultura sostenible. Cal destacar que la inseguretat alimentària no és un problema exclusiu de països en desenvolupament, sinó que als països anomenats desenvolupats part de la població té problemes per a garantir una nutrició adient. Per altra banda, encara que gran part del debat al voltant de la SA s'ha centrat en aspectes relacionats amb l'accessibilitat i la producció d'aliments, s'observa una tendència cap a un concepte més integral de la SA que abasta també els canvis ambientals globals. Per aquesta raó, investigadors, governs i organismes internacionals estan proposant mesures de diversa índole, enfocades a garantir la seguretat alimentària i nutricional de la població, d'una banda, i a contrarestar els impactes negatius que les activitats de producció i consum d'aliments tenen sobre el medi ambient i el canvi climàtic. En aquest sentit, el registre de dades relacionades amb variables econòmiques i ambientals, conjuntament amb el coneiximent d'experts en aquestes àrees i l'ús d'eines d'estadística aplicada, han contribuït a que a partir de evidències objectives es formalitzen de forma estructurada i coherent les accions que poden modificar el comportament social i econòmic de tots els agents involucrats. En aquest context, la teoria econòmica en general, i la teoria del consumidor en particular, a partir del registre i processament detallat d'informació estadística relacionada, han fet possible analitzar alguns aspectes de les actituds, comportaments i preferències del consumidor. Aquests aspectes poden ser utilitzats com a senyals de les possibles reaccions que els consumidors tindrien en la seua demanda per alguns aliments davant canvis en variables de mercat que no pot controlar, com ara els preus, o davant accions de política pública que també poden modificar les seues decisions de consum, tals com l'aplicació d'impostos i/o subsidis, els quals finalment afectaran les seues metes alimentàries i nutricionals. D'altra banda, l'anàlisi de cicle de vida (ACV) ha adquirit una gran fortalesa per a la avaluació ambiental. En concret, l'ACV en la seua variant conseqüencial (ACV-C) presenta interès per a la valoració de les possibles conseqüències sobre el mediambient davant canvis exògens en variables econòmiques o de política medioambiental. En la literatura relacionada amb l'ACV-C s'utilitzen paràmetres econòmics como ara les elasticitats, per a conèixer la denominada relació de substitució entre productes alternatius. En general, una elasticitat es una mesura quantitativa que relaciona el canvi percentual en quant a quantitats d'una variable en particular amb el canvi percentual que té qualsevol altra variable. D'aquesta manera es poden modelar els canvis que es presenten a curt i llarg termini em els indicadors mediambientals a conseqüència de canvis en variables como ara els preus o la quantitat d'inputs utilitzats en la producció d'un bé o servei. Davant d'aquest escenari, l'objectiu d'aquesta tesi es proposar noves metodologies per a avaluar la seguretat alimentària (SA) i la sostenibilitat ambiental associada al consum d'aliments, amb la fi de promoure una seguretat alimentària sostenible. Els casos d'estudi desenvolupats se centraran en Espanya, i s'utilitzaran eines metodològiques que involucren l'aplicació de la teoria del consumidor, la perspectiva de cicle de vida i alguns mètodes estadístics. L'abast del objectiu plantejat s'ha aconseguit a partir de quatre objectius secundaris, i cadascun d'ells ha quedat reflectit en respectius capítols de la tesi, dels cuals dos s'han centrat en analitzar la seguretat alimentària, i els dos restants en els aspectes medioambientals. / [EN] The second of the UNO's Sustainable Development Goals is zero hunger. The aim is to end hunger, achieve food security (FS) and improved nutrition and promote sustainable agriculture. It must be highlighted that food insecurity is not a problem exclusively for developing countries, but in the so-called developed countries, part of the population has also problems to achieve adequate nutrition. On the other hand, although to date much of the debate on FS has focused on aspects related to accessibility and food production, there is a trend towards a more comprehensive concept of food security that also encompasses global environmental changes. Thus, researchers, governments, and international organizations as FAO are proposing various measures and focused on guaranteeing food and nutritional security of the population and, in addition, on counteracting the negative impacts that food production and consumption generate on the environment and climate change. Along these lines, the recording of economic and environmental data, together with experts' knowledge in these areas, and the use of applied statistics are fundamental so that, from objective evidence, actions to modify the economic and social behavior of the individuals involved be formulated in a structured and coherent way. In this context, the economic theory in general, and the consumer theory in particular, accompanied by detailed recording and processing of statistical information, have made possible to analyze many aspects related to the attitudes, behaviors, and preferences of consumers. These aspects may be used as signals of their possible consumers' demand reactions for some foods in the face of changes in market variables that they cannot control, such as food prices, or in the face of public policy actions that may also alter their decisions such as taxes and /or subsidies, which will ultimately affect your food and nutritional situation. On the other hand, Life Cycle Assessment (LCA) has gained great importance as to environmental assessment. Specifically, consequential LCA (C-LCA) arises as a tool to assess the potential consequences on the environment in view of exogenous changes in specific economic variables, or environmental policies. When reviewing the literature on C-LCA, elasticities are used to find out the so-called substitution ratio between alternative products. Generally, an elasticity is a quantitative measure that relates the percentage change of a specific variable with the percentage change of another variable. In this way, we can model short and long term changes of the environmental indicators as a consequence of changes of variables such as the price or the amount of inputs applied in the production of a good or service. Taking the foregoing, the objective of this dissertation is to propose new methodologies to evaluate Food Security (FS), and the environmental sustainability associated with food consumption, in order to promote a sustainable food security. The case studies developed will be focused on Spain, and methodological tools that involve the application of consumer theory, LCA, together with statistical methods will be used for this. The scope of the stated objective has been achieved from four secondary objectives, each of them reflected in respective chapters of this dissertation. Two of the chapters focus on analyzing food security, and the remaining two on environmental aspects. Initially, in the absence of FS measurement tools that allow the formulation of strategies in terms of regions or regional blocks, a new methodology for measuring food insecurity based on the dimensions of access and stability consumption is proposed and implemented in chapter 2. To this aim, the values of different price and income elasticities for nine animal sourced foods (ASF) are integrated by using quarterly data of for the period 2004-2015 in the 17 Spanish regions. The results / Forero Cantor, GA. (2020). Incorporación de consideraciones de estabilidad y sostenibilidad ambiental en la seguridad alimentaria. El caso de España [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/158733 / TESIS