The more, the merrier': John R. McCulloch and the 'Corn Model

This paper offers new textual evidence supporting the Sraffian 'corn-ratio' interpretation of David Ricardo's early theory of profits. We analyze the first edition (1825) of John Ramsay McCulloch's Principles of Political Economy, arguing that it provides a clear articulation of the profit rate’s physical determination. McCulloch, Ricardo’s pupil, defines profit as the excess of commodities produced over those expended in production and calculates the profit rate directly in physical quantities of corn. This finding parallels the evidence found in Torrens, ultimately reinforcing the argument that the ‘corn model’ was deeply rooted in the early classical tradition. At last, our comparative analysis contrasts this initial, clear physical framework with McCulloch’s later shift towards value-centric reasoning.