224 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

diate or primary factors, and similarly all outputs produced should
be assigned values; market prices when available. shadow prices
when necessary.
And, finally, if I have another 30 seconds, I should like to say
something about the relationship of my thinking with Professor
FriscH's, He asserts that one should begin with a social objective
function or some measure of social welfare. My own contribution,
if it be a contribution, is merely to set forth a way to discover
certain aspects of the social welfare function. I do not feel that we
can begin with it literally because at the beginning we do not know
what it is. We must discover it by trying out proposals and seeing
how the public and political organs react to them. In this way social
preferences will be revealed, and a social welfare function will be
discovered which can be used in designing and appraising investment
 projects.

51 Dorfman - pag. 38