L'ALLOCATION DES RISQUES DANS LES CONTRATS :: DE L'ECONOMIE DES CONTRATS ‘INCOMPLETS' A LA PRATIQUE DES CONTRATS ADMINISTRATIFS

International audienceRisk allocation in contracts is an important issue for both economics and law. It questions the theorerical, methodological, empirical foundations of economic and legal analysis. It also offers a valuable ground for comparative legal-economic inquiry. The article aims at providing some insights into that general perpective, and proceeds with an articulation of theoretical and empirical analysis. The paper first offers a critical analysis of some key economic basis hypothesis on law, contract law and legal institutions, notably the courts. It concentrates on various componants of the New Institutional Economics stream that are something to do with the notion of contractual incompletedness. The emphasis is put on two central issues : the contract-institutions relations, and the scope of incompleteness as a guide for empirical research into the economic dimensions of contract law. The second part of the article compares and evaluates the significance of the economic concept of incompletedness and theFrench legal notion of imprévision, which relates to a notion that the administrative courts have set-up to decide cases in which the occurrence of unforeseen events affects the contractual equilibria built ex ante. The analysis then moves toward the research of a legal and empirical translation of uncertainty of the future. The article argues that positive legal provisions in contract law enable co-contractors to set-up a framework in which the consequences unforeseen events can be adressed. Legal provisions such as those which relate to conditional duties, aleatory contracts, force majeure, fortious events, price revision, hardship, are examples of tools that allow a significant amount of previsibility in contractual relations, particularilly long-term contracts. We then offer an empirical analysis of a specific legal notion : the imprévision. The analysis is based on legal data, namely the French Conseil d'Etat decisions that deal with a request for compensation by the State of the economic consequences of the occurrence of unforeseen events for the suppliers. A descriptive statistical analysis is associated to a study of the doctrine that the State officials adress to contracting officers ; a comparison of price determination provisions under American procurement and French law of “marchés publics” is then made.L'allocation des risques inhérents à l'exécution d'obligations dans des accords dont la temporalité est longue est une question importante, notamment pour l'économie. Or, à cet égard, il est significatif de constater que les entrées consacrées au droit administratif dans l'Encyclopedia of Law and Economics ne font pas mention des contrats administratifs, et que les entrées relatives au droit des contrats ne renvoient jamais au droit administratif. On ne peut que signaler, à ce propos, l'originalité de l'ouvrage de microéconomie des marchés publics et de la réglementation de J.-J Laffont et J. Tirole (1993). Quelles conclusions tirer de ce constat ? De notre point de vue, deux hypothèses peuvent être avancées : soit les économistes se désintéressent des contrats administratifs, soit ils les intègrent implicitement dans le même moule que les contrats de droit privé. Nous estimons que la deuxième hypothèse est la plus plausible, et nous souhaitons l'explorer ici en réfléchissant sur le fait de savoir si le droit positif des contrats privés et administratifs rend possible l'application de mêmes catégories d'analyse en matière d'allocation des risques. Cette question appelera naturellement une réflexion sur la signification et la portée empirique de la notion économique d'incomplétude des contrats