Sraffa, Marshall and the principle of continuity

This article addresses Piero Sraffa's critique of Alfred Marshall's supply-and-demand framework, and Sraffa's later book Production of Commodities, taking into account an aspect that has been relatively neglected in the literature, namely the ontology underlying the conceptions of Sraffa and Marshall. This ontological dimension can be best understood through Sraffa's critique of the principle of continuity. The principle of continuity was used by Marshall as a methodological justification for the use of partial equilibrium methods in the analysis of supply and demand, in a context where different causes are deeply interconnected. Sraffa acknowledges the existence of interconnectedness, but rejects Marshall's methodology, which is based on the principle of continuity, as it becomes clear in his unpublished manuscripts, which are examined here.