What I'm trying to say, Jim, is that to observe prices and to conclude from these observations about theoretical values and theoretical utility/productivity is to go in the wrong direction. I always thought that theory should explain the world, not the other way around.
Jonathan Nitzan http://www.bnarchives.net
Devine, James wrote:
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
