Nitzan and Bichler's critique of Marxism is moronic and vulgar, and here's why.
Empirics aside, if you actually boil it down, their critique is that (certain) abstractions aren't real because they aren't directly observable. What N&B are missing is that they literally don't believe in abstract labor. They're sort of anti-value theorists in that they think value theory is impossible (either Marxian or Neoclassical). This is really just a philosophical argument posing as an empirical one. The critique hinges on the ontological and epistemological status of abstractions, specifically the concept of abstract labor in Marxist theory.
They're right to note that without abstract labor as a real abstraction, Marxian value theory collapses, because there is no measurable or material basis for value production and the link between labor time and prices becomes untenable. But this isn't the dunk they think it is.
If you reject abstract labor, by extension, you reject value theory. Marx’s point that such abstractions are real precisely because they operate as socially embedded realities in capitalist systems. Abstract labor is a real abstraction. Real abstractions are abstractions that arise not merely as mental constructs but as material and social realities within specific historical contexts, especially in capitalist societies. They are "real" because they are embedded in the actual practices, institutions, and relations of production, not just in thought.
Abstract labor is a dialectical category because it arises from the concrete diversity of human labor but negates that diversity by reducing it to a single, measurable abstraction. At the same time, this abstraction organizes and dominates the concrete activities of production and exchange in capitalism.
If you deny the ontic validity of real abstractions of course you will reject value theory, but thats not an "own".
>As a rule, the most general abstractions arise only in the midst of the richest possible concrete development, where one thing appears as common to many, to all. Then it ceases to be thinkable in a particular form alone. On the other side, this abstraction of labour as such is not merely the mental product of a concrete totality of labours. Indifference towards specific labours corresponds to a form of society in which individuals can with ease transfer from one labour to another, and where the specific kind is a matter of chance for them, hence of indifference. Not only the category, labour, but labour in reality has here become the means of creating wealth in general, and has ceased to be organically linked with particular individuals in any specific form. Such a state of affairs is at its most developed in the most modern form of existence of bourgeois society—in the United States. Here, then, for the first time, the point of departure of modern economics, namely the abstraction of the category 'labour', 'labour as such', labour pure and simple, becomes true in practice. The simplest abstraction, then, which modern economics places at the head of its discussions, and which expresses an immeasurably ancient relation valid in all forms of society, nevertheless achieves practical truth as an abstraction only as a category of the most modern society …
>… This example of labour shows strikingly how even the most abstract categories, despite their validity—precisely because of their abstractness—for all epochs, are nevertheless, in the specific character of this abstraction, themselves likewise a product of historic relations, and possess their full validity only for and within these relations.
>Bourgeois society is the most developed and the most complex historic organization of production. The categories which express its relations, the comprehension of its structure, thereby also allows insights into the structure and the relations of production of all the vanished social formations out of whose ruins and elements it built itself up, whose partly still unconquered remnants are carried along within it, whose mere nuances have developed explicit significance within it, etc. Human anatomy contains a key to the anatomy of the ape. The intimations of higher development among the subordinate animal species, however, can be understood only after thePost too long. Click here to view the full text.