(16) F. Momigliano, “Economia industriale e teoria dell’impresa", Il
Mulino, Bologna 1975, pag. 575.
      (17) Idem.
      (18) L. Gallino, op. cit., pag. 26-27.
      (19)        Robert M. Solow, “Technical change and the aggregate Production Function", in “The review of economics and statistics , Agosto 1957.
(20)
dY
dt
dA
dt
F (K, L) + A
dF
dt
                                                               _dF^__9F_ _dKL ^_9F_ dL dt 9K dt 9L dt
dY                  9F dK H 9F   dL 
dt --- F (K, L) T A 9K dt H h 9L dt 
   dt                               
Y _ A , A             , _l._k
Y  A +A 9KK Y K+A9L Y L
ma:
                   3Y = 3F 3Y _ 3F 9K A 9K ; 9L A 9L
                 0 = .JK_           JY
                 P 9K Y ,U P' 9L
L,
Y

       Nell’illustrare i contributi metodologici di Solow, Massel e Kaldor, si seguirà, oltre ai testi originali, l’esposizione fatta da M. Arcelli in “La Cobb-Douglas...” op. cit.
       (21)       Luigi Pasinetti, “On concepts and measures of changes in productivity", The review of economics and statistics 1959; Benton F. Massed, “Investment, innovation and growth", Econometrica voi. 30, n. 2, Aprile 1962.
       (22)       “Obviously much, perhaps nearly all, innovation must be embodied in new plant and equipment to be realized at all. One could imagine this process taking place without net capital formation as old-fashioned capital goods are replaced by the latest models, so that the capital-labour ratio need not change systematically”. R.M. Solow, op. cit., pag. 317.
       (23)       Benton F. Massel, “Investment, innovation, and growth", Econometrica voi. 30, n. 2, Aprile 1962.
       (24) Nelle ipotesi di Massel gli investimenti I(t) si sviluppano
secondo la formula.
                                                                                               l(t)='l(0)ef3t
72