But, Marx, also, notes that its not only this change in the value of gold that affects the value of the standard of prices. The state that determines this standard, also determines how much gold it contains, i.e. what amount of social labour-time it actually represents. If the value of gold remains constant, but the state decrees that, henceforth, a £ will be equal to only 0.80 grams of gold, it means that the value of a £ is now equal only to 800 hours of social labour-time, not 1,000.
Equally, therefore, prices measured in these £'s will rise, and more £'s will have to be thrown into circulation. When the standard of prices loses any connection to a money commodity such as gold, its connection to social labour-time, however, remains. If, previously, a £, equal to 800 hours of social labour-time, required 1,250 £'s to be thrown into circulation, that will remain the case, because these 1,250 £'s, equal 1 million hours of social labour-time, the total value of commodities, whose equivalent they are. However, now, because in such a fiat system, these £'s cannot be redeemed for gold, if more than these 1,250 £'s are thrown into circulation, their total value, as money, remains 1 million hours of social labour-time, and so the value of each £ is proportionately reduced. If 2,500 £'s are put into circulation, each £ represents only 400 hours of social labour-time, and so prices measured in these £'s would double.
So, when Roberts says “if value grows, money supply will rise to match that value” this confuses and conflates money with currency, the error, also, made by Ricardo, as Marx points out. If value rises, then, as set out above, its equivalent form, i.e. its representation by money, does indeed rise, because this is a tautological relationship, but that is not at all the same thing as saying that “money supply”, i.e. the amount of money as currency will rise to match that value. It may be that the money supply, i.e. the amount of currency put into circulation may well be more or less than is required as the equivalent of this increase in value. For example, if the supply of currency remains constant, that would mean that each unit of currency, for example a £, would, then represent a greater quantity of social labour-time than it did previously, and the average unit prices of commodities would fall. If the total value of commodities rises by 10%, but the amount of currency put into circulation rises by 20%, then each unit of currency is devalued, represents a small quantity of social labour time than it did previously, and so average unit prices rise.
Roberts continues,
“However, new value growth (which we measure in hours of labour worked by the whole labour force in an economy) tends to slow relative to increased output of commodities. So prices per unit of output should tend to fall, as less labour time is involved in the production of output.”
Again, this is replete with errors and inaccuracies. New value growth is not measured by the increase in hours worked by the whole labour force, for several reasons. Firstly, the actual hours worked, are hours of concrete labour, and not the same as abstract labour, which is the measure of value. Secondly, even in terms of that abstract labour, it is only that labour that is socially necessary that is value creating. Thirdly, a lot of labour performed as set out earlier, is necessary for the functioning of society, and for the realisation of already produced value, but is not itself value creating.
Setting all that aside, Roberts' statement is still wrong, because as I have set out elsewhere, he has accepted what Marx called Adam Smith's “Absurd Dogma”, that the value of commodities resolves entirely into revenues, i.e. into the new value created by labour, which Marx shows is impossible.
Roberts wrote,
“The demand for goods and services in a capitalist economy depends on the new value created by labour and appropriated by capital. Capital appropriates surplus value by exploiting labour-power and buys capital goods with that surplus value. Labour gets wages and buys necessities with those wages. Thus it is wages plus profits that determine demand (investment and consumption)”,
which is simply Say's Law as amended by Keynes to account for savings and net investment.
The new value created is equal to v + s, i.e. the current labour performed, whereas the total value of output is equal to c + v + s. So, Roberts, like Smith and Say, (and Keynes) cannot explain where the demand for c comes from. V is paid in wages, and forms the demand for wage goods, whilst s forms the revenues of rent, interest, taxes and profit of enterprise which fund the personal consumption of the exploiting classes, and their state, as well as any any accumulation of capital (itself divided into c + v), but that leaves Roberts as with Smith, Say and Keynes having to explain where the demand for c itself comes from! Given that, as Marx sets out, c forms the largest and growing (as a result of rising productivity, as the basis of the tendency for the rate of profit to fall) component of production, both physically, and in terms of value, that is rather a large black hole in demand that Roberts cannot explain.