Apriorisme et théorie économique

[eng] It may be strange to write about Apriorism at a time of high Empiricism. However, when looking from a critical point of view on Apriorism and in particular on the arguments of its advocates in Economic Sciences, we must necessarily recognize the importance of a correct practice of refutation. The necessity of a serious study of the methodological conventions of refutation is here affirmed. considered as taken into account through a suitable définition of production or consumption sets. However, if one wants thé choice of a location to be controlled by the agents, it is a well knouw fact that one has serious difficulties with non-convexities. Such a representation is necessary to build a meaningful theory of local public goods : in such a case one can enjoy a public good only by choosing a location in which this public good is available.. This model has to be considered as a polar case with respect to the classical models of general equilibrium. The commodities are fixed, in thé sensé that they cannot be moved from one location to another. Only the agents can move, and they chose the best location from the point of view of their own welfare.. There are three parts to this paper.. First I try to analyse how the individual welfare changes when the number of people in a given location changes. This is, in some sense, the old problem of the optimal population. . The second part is devoted to defining suitable concepts of equilibrium and stability. Standard conditions of existence and stability are presented. In the last section, I study Pareto optimality, showing the necessity of being careful when transposing classical concepts. For instance, there are stable equilibria which. are not Pareto optima ; this creates new difficulties in interpreting the well known argument by Tiebout. [fre] II peut sembler paradoxal d'écrire sur l'apriorisme à une époque où l'empirisme paraît être de rigueur. Cependant, à l'occasion d'un examen critique de l'apriorisme en général et des arguments de ses partisans économistes en particulier, surgit une notion fondamentale, celle d'une pratique correcte de la réfutation. L'article affirme la nécessité d'un examen sérieux des conventions méthodologiques de réfutation qui sont employées par les économistes.