 Marxist claims about exploitation are often said—by both Marxists and their critics—to depend on the labour theory of value. This is denied by Cohen who, in a well-known article, argues that the relation between the two, despite their long historical association, is one of mutual irrelevance (1988: 209). The labour theory of value is understood here as a theory of equilibrium price, whose central claim is that magnitude of value is determined by socially necessary labour time. Cohen suggests that those Marxists who have insisted on the labour theory as the basis of exploitation have confused the idea of producers creating value with the idea of producers creating that which has value (the product). This latter, somewhat simpler, idea is the real basis of the charge of exploitation. What matters for exploitation is not that capitalists appropriate value created by workers, but rather that they appropriate (part of) the value of what the worker produces.