As maintained by J. M. Clark the amplitude of the investment cycle is larger and that of the consumption cycle smaller than that of the income cycle, provided only the consumption constant is larger than zero. On the other hand, it is true that acceleration is neither a necessary nor a sufficient condition for magnification: not a necessary condition since (4) is independent of the investment function; not a sufficient condition since, for co = o, magnification is absent regardless of the investment function and even if Baumol's equation (3) were valid and his conditions for magnification were satisfied.