Revue économique - Année 1969 - Volume 20 - Numéro 6 - Pages 954-967This paper shows how The general economic theory of congestion published elsewhere can be extended to the case where there may be several types of quantities of the service several qualities affected by these quantities through the congestion effect and several instrumental parameters by which one can directly influence these qualities. The optimum and the optimal price taking into account these congestion externalities are characterized. When the congested service is sold at this optimal price the fact that the resulting budget is balanced or shows deficit or surplus depends upon the structure of qualitative return to scale of the congestion function i.e on technical characteristics of the relation by which qualities depends upon quantities. This paper shows how The general economic theory of congestion published elsewhere can be extended to the case where there may be several types of quantities of the service several qualities affected by these quantities through the congestion effect and several instrumental parameters by which one can directly influence these qualities. The optimum and the optimal price taking into account these congestion externalities are characterized. When the congested service is sold at this optimal price the fact that the resulting budget is balanced or shows deficit or surplus depends upon the structure of qualitative return to scale of the congestion function i.e on technical characteristics of the relation by which qualities depends upon quantities. 14 pages Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.