Answer:
In [651], Gil placed great stress on the "1 quarter of corn = x cwt of
iron" being an "*equation*". He went on to add:
> Saying one bundle is exchanged for another is not generally the same as
> saying that one bundle equals another.
My response in [658] was intended to show that simply because there is
an "=" sign does not establish that 1 side of the "equation" is equal to
the other side in all respects.
Chai-on points to the difference between identity and equality.
Yet Gil had previously in [653] quoted Tarski as suggesting that "the same
meaning is ascribed".
So perhaps Chai-on is using different definitions of equality and identity
than those used by Tarski and Gil.
Let's step back a moment.
*Every* economic theory has a theory of value (whether it is explicitly
stated or inferred).
One of the major questions that a theory of value answers is: what
determines exchange-value? If you can't answer that question, then you
can't have a theory of (any type of) price either.
Obviously, it would be a tautology to say that exchange-value determines
exchange-value.
Is it marginal utility, as suggested by the marginalists? If Gil and Steve
think there are problems with Marx's theory, what about the marginalists'
theory? E.g. what is a "util" and how is that fiction measured?
A theory of value could be based on physical quantities. If that is the
case, how does money enter the picture except as a numeraire?
What I don't hear Steve or Gil suggesting, then, is an *alternative*
theory of value.
In solidarity, Jerry