The preparation of economic budgets. Economic budgets must fulfil two aims : providing a short term forecast (one to two years) covering the national economic activity as a whole, and making a contribution to the definition and study of economic policy decisions, in their broad lines. The authors of this study begin by recalling when and by whom these projections are made, what types of information are used and how the work is organised. Methods and utilisations are then examined, for forecast budgets and exploratory budgets successively. The distinction between these two major types of economic budget can be made as follows. Exploratory budgets are prepared before the Government has built the Finance Bill for the year in question (these projections for a year N, are made therefore before the month of May, N-l) ; forecast budgets are based on a Finance Bill already drawn up or passed. This last type of projection is the best known and most « classical » ; on the other hand, the preparation of exploratory budgets is of more recent origin, and their methodology is both little known and still uncertain. The main characteristic of the forecast budget is that it is constructed on the basis of very detailed information, not only the Finance Act, but also a mass of information concerning the recent trend of the economic situation and the intentions of economic transactors. The exercise is therefore essentially a compilation, a test of consistency, and a consolidated presentation of various informations, within the framework of the national accounts. It makes it possible to replace sectoral views of economic activity in an exhaustive overall view, and therefore to follow, with a view to any necessary modifications, the execution of the economic policy previously decided upon. The perfecting of the forecast budget implies an extension and improvement of statistical information, and a bringing into line of the techniques of the projection of national accounts and of very short term forecasting based on the analysis of various economic indicators. The exploratory budget can use only a very small volume of information about the year under study ; it therefore requires the use of a more complex model than that of the forecast budget. The model of the French exploratory budget is still fairly simple and is being progressively improved ; it is used to make not one projection, but several variants. One of the purposes of the exercise is to try to define a strategy of cyclical policy in relation to the achievement of the targets set in the medium term Development Plan. Altough some progress has been made, the techniques used do not yet make it possible to reduce uncertainty and forecast economic processes sufficiently to ensure this result.
L'exposé qui suit ne vise pas seulement à décrire les méthodes utilisées en France pour l'élaboration du budget économique annuel. Il tend également à montrer le rôle joué par celui-ci au sein de l'Administration et l'utilisation qui est faite des divers types de projection à court terme. On n'a pas indiqué systématiquement dans le cadre de cet article quelles sont les diverses relations entre grandeurs économiques admises dans les exercices de projection, car ces relations ne sont pas toujours explicitées, ou ne gardent pas une expression quantitative immuable. Par contre, on a précisé la structure logique des interdépendances admises dans les modèles de projection, et indiqué les principales sources d'information dont on dispose pour effectuer une prévision.
