Socially Necessary Labour Time - Criticism

Criticism

Marx's interpretation of value from the perspective of society as whole proved elusive for many critics. Marx tried to answer them, in a letter to a friend, Dr. Louis Kugelmann:

"All that palaver about the necessity of proving the concept of value comes from complete ignorance both of the subject dealt with and of scientific method. Every child knows that a nation which ceased to work, I will not say for a year, but even for a week, would perish. Every child knows, too, that the masses of products corresponding to different needs require different and quantitatively determined masses of the total labour of society. That this necessity of the distribution of social labour in definite proportions cannot possibly be done away with by a particular form of social production but can only change the mode of its appearance, is self-evident. No natural laws can be done away with. What can change in historically different circumstances is only the form in which these laws assert themselves. And the form in which this proportional distribution of labour asserts itself, in a state of society where the interconnection of social labour is manifested in the private exchange of the individual products of labour, is precisely the exchange value of these products. "Where science comes in is to show how the law of value asserts itself."

Despite these comments, Marx has been criticised strongly for adding the "socially necessary" qualification to labour time by the libertarian philosopher Robert Nozick in Anarchy, State and Utopia, for whom it is an unjustified 'bolt-on' aspect of Marx's theory.

One debate in Marxian economics concerns the question of whether the product-values formed and traded include both direct and indirect labour, or whether these product-values refer only to current average production costs (or the value of current average replacement costs).

Mirowski (1989) for example accuses Marx of vacillating between a field theory (labour-time currently socially necessary) and a substance theory of value (embodied labour-time). This kind of criticism is due to a confusion of the process of labour in general (adding use to a product, which under capitalism equates adding value to a commodity) with the task of quantifying the exchange value added. The general process affixes labour time to a commodity, and providing the commodity functions as such the quantity of labour time is immaterial - an abstract unknown, so to speak - and can be expressed in many ways, e.g. "embodied in", "attached to", "associated with", etc. Quantifying the amount of labour time associated with commodities requires focus on the social, shifting character of socially necessary labour, and specifically recognition that the quantities are 'current' i.e. incessantly changing. Today's value is different from yesterday's and tomorrow's, and the amount of value can only be determined numerically on the basis of a given point in time at which values are realized simultaneously at specific prices. Thus Marx's theory is best interpreted as a field theory, but for the reasons just stated, modelling the determination of value by socially necessary labour time mathematically is a difficult exercise if not probably impossible.