I agree with Andrew that we need to explain why the law of value holds
and that this is a theoretical problem, but this is an instance of
how empirical investigations are an indespensible requirement of a
productive research program. It is in confrontation with the real
that we can get a sense of what are the right questions to pose to
theory. There is an infinity of possible worlds with an infinity of
theories to account for them, since we can only pursue a few of these
it is more productive to pursue the theories that account for our
world.
I agree that we also need to have a theory that accounts for the
instances where there are divergences between the profits accruing
to industries and what one would expect these to be on account of the
labour employed. But to produce such a theory we need some facts.
What types of industries actually report higher profits than one
would anticipate their surplus value to account for?
Unless one goes through the basic classificatory phase, the collection
of type specimins etc, one lacks the theoretical raw material upon
which to build ones theory.