Information asymmetries and strategic behavior in the instrumentation of the common agricultural policy.

Summary The purpose of this thesis is to study the regulatory instruments available to the European Union (EU), and more generally to a government, to achieve its objectives in the agricultural sector. The partial framework of analysis. The focus is on recent developments in this theory, and in particular the modeling of incentive mechanisms, which are very well suited to contractual policies and tendering systems. Two instruments used by the EU, which more specifically concern the production and marketing of cereals, are thus analyzed: a policy of restricting supply through the land input, commonly called "set-aside", and "export refunds", which are systems of aid to exports that operate, in part, through tendering. The traditional theory of welfare is the subject of the first part. Recent developments in this theory as applied to the agricultural sector of developed economies are presented. The theory of mechanisms is then presented. This second part deals in particular with the mixed problems of asymmetric information, mixing anti-selection and moral hazard, which correspond to the general case of regulation by production. We are particularly interested in the properties of threshold mechanisms. The last part of this thesis is more specifically devoted to the study of two European agricultural policies. The first is a contractual policy of supply control through input, adopted at the end of the 1980s. The second concerns the sale of grain stocks that the community builds up through its intervention in the market.