This is in response to Chai-on Lee (653) and Steve Keen (611).
Chai-on writes:
Yes, as you said, "the 'assumption'[LVT] is not made out of thin air,
but is instead based on a certain type of analysis of the commodity". An
assumption is usually pregiven, is not derived from a certain **explicit**
analysis as far as we know. In Marx's case, he derived it from the
analysis of the commodity. In other sciences, however, such an analysis
is not explicitly described but is hidden from behind. They start directly
from the assumption. Yet Marx deliberately demonstrated how he derived
the LVT. In that sense, the LVT is somewhat different from the usual
assumption. I am not sure yet what I should call it instead of the
assumption. But I dissent from calling it an assumption.
My response:
I am not sure whether or not one should call the LTV an assumption. And I
agree that, whatever we call it, it is different from the assumptions in
other economic theories. But I also argue that Marx's argument in Section 1
of Chapter 1 is not - and was not intended to be - a logical proof in the
sense that it is proven logically that the LTV absolutely has to be true.
Instead, Marx derived the LTV from an analysis of the commodity which was
based on certain methodological presuppositions about how a theory of
capitalism should be constructed. The two main methodologicial
presuppositions relevant to the derivation of the LTV are:
1. Capitalism should be analyzed in terms of its OBJECTIVE
characteristics, not in terms of the choices of individuals. One could
call this method an objective method, as opposed to a subjective
method. The first objective characteristic of capitalism, with
which Marx began his analysis of capitalism, is that its product
is a commodity.
2. The commodity as a product of capitalism is analyzed as a GENERAL
EQUIVALENT to all other commodities, such that the exchange of
commodities is considered to be essentialy an EXCHANGE OF
EQUIVALENTS.
However, these methodological presuppositions are not self-evidently true
and in fact most economists would disagree with both of them. Therefore,
even if Marx's logic is impeccable, such that the LTV follows of necessity
from these methodologicial presuppositions, this still does not constitute a
"logical proof" in the above sense, because these methodological
presuppositions may be (and usually are) rejected.
I argue that there is no way to decide the validity of Marx's methodological
presuppositions (compared to other presuppositions) on purely theoretical a
priori grounds. The relative validity of these fundamental methodologicial
presuppositions depends rather on their relative explanatory power.
Steve adds (laying some groundwork for his argument that use-value is also a
source of value) that:
However, the fact that Marx began from a set of
axioms which did not presuppose the conclusion that
labor is the only source of value is a methodological
advance over beginning with that assumption.
My reply:
I agree that the LTV is derived, rather than simply assumed, as argued above.
However, I disagree with you in the sense that I would argue that, if Marx's
methodological presuppositions are accepted, then the LTV follows of
necessity. On the basis of these presuppositions, there is no other
possible source of value -
a common homogeneous property of commodities - besides labor.
Fred Moseley