Empirically, one can only get as far as establishing a " grand average " for the price of an hour of work ( this is often referred to in Marxian economics as the " monetary equivalent of labour time ", or MELT ) and one can discuss the extent to which labour is undervalued or overvalued in a " relative " ( comparative ) sense.
42.
Proponents of the temporal single system interpretation such as Moseley ( 1999 ), who argue that the determination of prices by simultaneous linear equations ( which assumes that prices are the same at the start and end of the production period ) is logically inconsistent with the determination of value by labour time, question whether the mathematical proof that Marx's transformation problem has no general solution.
43.
In another classical tradition, Marx distinguished between the " value in use " ( use-value, what a commodity provides to its buyer ), labor cost which he calls " value " ( the socially-necessary labour time it embodies ), and " exchange value " ( how much labor-time the sale of the commodity can claim, Smith's " labor commanded " value ).
44.
In Marx's finished theory, presented in " Capital, Volume III ", the " value " of a commodity turns out to be " its socially average, current replacement cost in labour time " ( a synchronic economic reproducibility cost ), but this particular labour requirement turns out to be quite a different quantity than " both " " labour embodied " " or " " labour commanded ".
