Exploitation and productiveness: the generalised commodity exploitation theorem once again

In a recent contribution on this journal, Matsuo (2009) has provided an interesting argument to refute the Generalised Commodity Exploitation Theorem (GCET), by highlighting a potential asymmetry between labour and other commodities. In this paper, a novel characterisation of the relation between exploitation and productiveness that is at the heart of the GCET is proved. This result is interesting per se, because it is weaker and more general than the standard GCET. But, owing to the rigorous specification of all the relevant conditions, it also clarifies the structure of Matsuo’s argument, and its dubious theoretical features. It is also argued that, even if Matsuo’s formal argument were deemed convincing, a revised version of the GCET can be proved, which reinstates the symmetry between labour and other commodities in the standard Leontief setting.