L'allocation des risques dans les contrats : de l'économie des contrats « incomplets » à la pratique des contrats administratifs

Risk allocation in contracts : from the economics of incomplete contracts to the effective practices in administrative contracts Risk allocation in contracts is an important issue for both economics and law. It questions the theoretical, methodological, and 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 approach, and proceeds with an articulation of theoretical and empirical analysis. The paper first offers a critical analysis of some key economics based hypothesis on law, contract law and legal institutions, notably the courts. It concentrates on various components of the New Institutional Economics stream that have something to do with the notion of contractual incompleteness. The emphasis is put on two central issues : the contract~institutions relationship, 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 incompleteness and the French 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 as set up 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 of unforeseen events can be addressed. Legal provisions such as those which relate to conditional duties, aleatory contracts, force majeure, fortuitous events, price revision, hardship, are examples of tools that allow a significant amount of previsibility in contractual relations, particularilly longterm contracts. We then offer an empirical analysis of a specific legal notion : imprévision. The analysis is based on legal data, namely the French Conseil d?État 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 legal instructions given by the State to its contracting officers ; a comparison of price determination provisions under American procurement and French law of marchés publics is then made.