Ludwig von Mises' calculation argument against socialism is of fundamental importance to the modern-day case for the market. Yet it is to Hayek that some Austrian-influenced theorists turn when responding to the computational models for non-market price fixing proposed by some socialists. Their reading of Hayek's epistemological argument for markets as distinct from Mises' calculation argument needs to be questioned. Hayek's emphasis upon the dispersal of knowledge across space and time is consistent with Mises' position. In spite of his philosophical critique of rationalist constructivism and his treatment of tacit knowledge, Hayek's case for the market ultimately relies upon the Misean calculation argument. Hayek's work is therefore best understood as a shift in emphasis rather than as a philosophical departure from Mises' position.