SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIOUE ETC. 85 follows from the invariante of the composition of the labor force (1). Any assumption concerning the amortisation function <(6) of primary income can therefore be tested against observed realitv from three points of view: 2) The composition of global production P* in terms of con- sumption goods and investment goods, and the amortisation schedule for investment goods and durables; b) The structure of reproducible capital; cr) The composition of the labor forc.. 3) The shape of the amortisation schedule ç,(6) for any particular economic sector i generally bears little relation to an exponential curve, at least for sufficiently low values of 6. 7:(0)d0 represents the share of primary income which will emerge in consumed income during the interval 6 to 6 +de. But, taking steel manufacture as an example, the industry’s output can only enter final consumption after a period of at least some months; it must first pass through a number of intermediate stages. It follows that primary income absorbed by the steel industry can only emerge into final consumption after a certain lapse of time. The function ¢(8) thus starts with a value of zero, grows, reaches a maximum and then declines. The same is true of the majority of economic sec- tors (3). Naturally, 333-1) R.ÿ(0) = 4 R oi 9," where R,; 1s the primary income devoted to sector () § 120. () The shape of the majority of ¢(0) functions is therefore similar to that of the function « (0) which corresponds to the para-exponential model >xamined in annex (Section II A, $ 520 to 524). - oq Allais - pag. 135