Doctor of Philosophy / Department of Economics / Philip G. Gayle / My dissertation is comprised of two essays in the field of industrial organization with an emphasis on the airline industry. In particular, I investigate how airline mergers and alliances affect the components of total cost. By using a methodology that does not require the researcher to have cost data, I am able to infer marginal costs, fixed costs and sunk costs changes associated with mergers and alliances. My first essay examines two recent airline mergers—Delta/Northwest and United/Continental. Most post-merger analysis in airlines disproportionately focuses on assessing price rather than cost changes. Perhaps one reason is that reliable price data are more readily available. Despite the difficulty of obtaining cost data, researchers have sought to empirically assess whether cost efficiency gains associated with a merger outweigh the increased market power of the merged firm. The results from my analysis suggest that both mergers are associated with marginal and fixed costs savings, but higher market entry costs. The magnitude of the cost effects differed across the mergers. Moreover, I find that the market power effects of these mergers were negligible. My second essay investigates the cost effects of the codesharing alliance between Delta, Northwest and Continental Airlines. Codesharing is one of the most popular forms of airline cooperation that allows an airline to market and sell seats on its partners’ flights as though it owns those flights. Studies have found that airline alliances have very little to no effect on total cost. Rather than analyzing cost as a whole, I study whether a disaggregate analysis on cost is more appropriate. I find evidence that forming an alliance helps generate more passenger traffic for the alliance partners thereby reducing the partner carriers' marginal cost. Even though the literature has found that the total cost effects to be small, an alliance can have a considerable impact on some components of cost.

Cette thèse de doctorat s’intéresse à deux thèmes distincts : la prise de décision en situation de risque et l’efficacité économique. Ces deux questions sont traitées dans un cadre empirique en utilisant des bases de données uniques. Le premier chapitre teste les modèles théoriques de décision en situation de risque sur des données réelles de paris hippiques pour identifier la théorie qui permet la meilleure description des choix des individus. Ce chapitre montre que les théories comportementales de la décision en situation de risque (théorie des perspectives cumulées et modèle de l’utilité dépendante du rang) sont mieux adaptées pour expliquer le comportement des parieurs observé dans les données que la théorie de l’utilité espérée. Le second chapitre estime l’effet d’une concentration entre deux grandes entreprises du secteur des transports urbains en France sur leurs coûts. Les résultats obtenus mettent en évidence que la fusion n’a pas entraîné de gains d’efficacité pour les parties à la fusion. Ce résultat s’explique notamment par le contexte dans lequel la fusion a été menée, en particulier les raisons du choix de la cible, la perception des clients et des employés de la fusion, les différences de culture entre les entreprises et la préparation opérationnelle de l’opération. Le troisième chapitre examine l’impact d’une plus grande discrétion dans les procédures d’appels d’offres sur la sélection des opérateurs, en particulier leur productivité. Le résultat principal est que la procédure qui accroît potentiellement le pouvoir discrétionnaire des acheteurs publics conduit à la sélection d’entreprises moins efficaces qu’une procédure n’impliquant pas ou peu de discrétion. Nos analyses complémentaires suggèrent que le résultat s’explique par l’effet d’une plus grande discrétion à l’étape de sélection des entreprises. / This doctoral thesis focuses on two distinct themes: decision-making in situations of risk and economic efficiency. These two questions are treated in an empirical framework using unique databases. The first chapter tests the theoretical models of decision under risk on bets on horseraces to identify the theory that allows the best description of individuals’ choices. This chapter shows that behavioral theories of decision under risk (cumulative prospect theory and rank-dependent utility) are better suited to explain the behavior of bettors observed in the data than the expected utility theory. The second chapter estimates the effect of a merger between two large companies in the urban transport sector in France on their costs. The results show that the merger did not result in efficiency gains for the merging parties. This result can be understood in light of the context in which the merger was conducted, in particular the reasons for the choice of the target, the perception of customers and employees of the merger, the differences in culture between the companies and the operational preparation of the merger. The third chapter examines the impact of greater discretion in tendering procedures on the selection of operators, particularly their productivity. The main result is that the procedure that potentially increases the discretion of public purchasers leads to the selection of less efficient companies than a procedure involving little or no discretion. Further analyzes suggest that the result is due to the effect of greater discretion at the screening stage.