SEMAINE D'ÉTUDE SUR LE ROLE DE L'ANALYSE ECONOMETRIQUE ETC. fa. In the neighborhood of a given situation the fundamental relationship (117-19) is derived from the assumption according to which the relation 110-1) SR, _p Ly Re yy is derived from (117-10) in the case of a dynamic process and applies when the use of primary factors (services rendered ™- labour and natural resources) over time is being studied. It can thus be seen that the fundamental relationship '117-19) of the present study results simply from the assumption of the existence, over a large range, of a valid index R of real national income at factor cost when conditions of optimum allocation of resources in the Paretian sense are satisfied Allais - pag. 5,