Was It a “Fatal Error”? Sraffa and Samuelson on Marshall's Partial Equilibria Method

Abstract

Abstract Sraffa's “On the Relations between Cost and Quantity Produced” (1925) and Samuelson's “An Exact Hume-Ricardo-Marshall Model of International Trade” (1971) presented a strikingly similar analytical argument regarding the theoretical domain of Marshallian partial equilibrium models. Yet they reached radically different conclusions from their analyses. This article addresses this theoretical puzzle and proposes a plausible solution. To this end, the article reconstructs the evolution of Sraffa's and Samuelson's thinking on Marshallian partial equilibrium analysis and the evolution of Samuelson's thinking regarding Sraffa's 1926 critique of Marshallian economics. Sraffa's unpublished manuscripts to which Samuelson did not have access during his lifetime are carefully examined. A change in Sraffa's assessment of Marshallian partial equilibrium methodology that occurred in the second half of the 1920s is highlighted. This leads to new insights into Sraffa's thinking on the role and significance of the case of constant costs within Marshallian economics.