Jonathan writes:
Let me paraphrase Jim Devine in neoclassical terms (find the
differences):
"try selling it [an old PC] on e-Bay! Then, following Keynes'
method, state the
price in wage-units. However, that would only indicate its
exchange-value (in terms of marginal utility/marginal productivity
commanded).
You could also make an old PC from old parts to get an
estimate of its marginal utility / marginal productivity. Since the main
problem with PCs is "moral depreciation" rather than physical
depreciation (after the first 90 days or so) that would give a
first-guess of the PC's marginal utility / marginal productivity."
I just wonder how we can tell the two stories apart.<
actually, the issue of Marx vs. neoclassical is more complicated.
Much of neoclassical economics is nothing but a formalization of
supply and demand, which then is glorified and made into a religion.
(Marginal utility is demand, marginal productivity is supply -- for
product markets.) Some even apply it on the macro-economic level.
(Alas, even some "radicals" do so. I remember a paper in the RRPE by
Frank Thompson which applies the fallacious aggregate production
function.)
Now, Marx never rejected supply and demand. Rather, he saw it as a
distraction. A focus on only S&D is a focus on merely the trading of
commodities and thus suffers from commodity fetishism, which prevents
an understanding of the class nature of capitalism. But S&D [which
Marx understood in a Smithian, not Marshallian, way] explained the
empirical fluctuations of prices around prices of production (centers
of gravitation). Forces of supply and demand also helped explain why
prices of production deviated from values. Even at the basic level,
demand played a role: a commodity that wasn't in demand wasn't a
commodity and had no value.
Now, if you want to reject supply and demand, that's fine. But it's
another issue. As is the rejection of marginal productivity and
marginal utility. The latter really add no new information to S&D,
while often hurting our understanding of them.
(Many theories can be use without measurement. The question is whether
we can claim that something can and cannot be measured at the same
time.)<
Some things can be measured in theory but not in practice. Or one can
get a first-guess estimate. Almost nothing in social science can be
measured exactly.
JD
