On recent reformulations of the labour theory of value

The paper discusses three redefinitions of the labour theory of value: the New Interpretation of Duménil and Foley, the approach of Wolff-Callari-Roberts, and the Temporal Single System approach. In them the labour theory of value loses the role of instrument for the determination of the rate of profit and becomes a gratuitous reinterpretation of independently determined prices as ‘representing’ quantities of labour value on the basis of the undemonstrated postulate that only labour produces exchange value. It is argued that these approaches are unable to defend the thesis that profits result from labour exploitation because such a thesis must rest on the causes of wages below their potential maximum, causes that these redefinitions leave unexplained and in fact open to neoclassical explanations. They evidence an imperfect grasp of the foundations of the thesis in Marx that labour is exploited, foundations better grasped by P. Garegnani and clarified here with an example.