Introduction

When I was a student, I read Alessandro Roncaglia’s illustration of Piero Sraffa’s con­tribution to the theory of prices, and some years later it was on his advice that I went to Cambridge and had a rather quick look at some of the papers Sraffa had left to Trinity College.

Since that travel to Cambridge, much of my time has been taken by research on the Sraffa Papers, and what is discussed in this chapter is only one of the many themes enshrined in them. Indeed, following the very opening propositions of Production of Commodities by Means of Commodities, as summarized by Roncaglia in his 1975 book—“in the first instance Sraffa demonstrates that when ‘commodities are produced by separate industries’ in a system of subsistence production (‘which produces just enough to main­tain itself’), ‘there is a unique set of exchange-values which if adopted by the market restores the original distribution of the products and makes it possible for the process to be repeated; such values spring directly from the methods of production’ ” (quotation is from the 1978 English version, p. 4)—we are led to the focus of this chapter: was not starting an analysis of price determination, as Sraffa did in the first section of his 1960 book, from “an extremely simple society which produces just enough to maintain itself” (p.

To answer the questions we have just asked, we will turn to a slightly different one, concerning the origins of Sraffa’s approach and of the schemes he employed in Production of Commodities. Indeed, during the two decades that have followed the opening of the papers of Sraffa to the public of scholars, the question of how he had come to con­ceive the schemes that in 1960 appeared in his book has been answered in different and sometimes contrasting ways. Three main interpretations have been put forward. A first interpretation indicated Marx’s Theories of Surplus Value and the reproduction schemes contained in the second volume of Marx’s Capital as Sraffa’s main source of inspiration (de Vivo, 2000 and 2003; Gilibert, 2001 and 2003).² Another interpretation has called attention to Sraffa’s reading of contemporary economists and to his interest in natural sciences (notably atomic physics and chemistry) as influences that may have led him to describe production processes as he did with his schemes (Kurz and Salvadori, 2004 and 2005; Gehrke and Kurz, 2006; Kurz, 2012). Thirdly, it has been argued that Sraffa’s schemes have been an offspring of an endogenous evolution that his thought would have gone through in the summer of 1927 (Garegnani, 2004 and 2005).

The latter interpretation, independently of specific weaknesses or merits of the oth­ers, has the advantage of pointing to a sequence of documents that allow formulation of a hypothesis concerning a precise line leading Sraffa toward his equations.

Garegnani grounded the part of his interpretation relating to the results reached by Sraffa in the summer of 1927 on a set of notes drafted by Sraffa as a basis for the lectures he had agreed to deliver in Cambridge during the coming Michaelmas term.⁵ In partic­ular, Garegnani stressed that, in the opening pages of those notes, classical economists were depicted as interested in a “philosophical”, or “pre-scientific”, approach where value was understood as expression of “a relation of commodities as a whole to man­kind” and of the “primitive notion that there had to be somewhere or other one single ultimate cause of value” (Sraffa Papers, D3∕12∕3∕9-10 [A4∕4iv-v]). Such a “primitive notion” was counterposed to what was described as a more properly scientific interest in the explanation of relative or individual prices, which had been developed by mod­ern theorists (Sraffa Papers, D3/12/3/10, 12 [A4/4iv, vi]). Shortly afterward, however, according to Garegnani, Sraffa, drafting the same notes, would have recognized the gen­eral importance of the classical authors’ search for an “ultimate cause” or an “ultimate standard” of value.⁶ Indeed, he came to state that also contemporary theories of value could not avoid having recourse to an “ultimate standard” or “common measure” of value (Sraffa Papers, D3∕12∕3∕17 [A4∕4xiii], D3∕12∕3∕41-42 [A4/14ii-iii]; see also Garegnani, 2005, 461-64).

In this chapter, we accept this general outline of the development in Sraffa’s thought in the summer of 1927 and concentrate our attention on some of its features and on aspects of Garegnani’s interpretation of subsequent developments. However, before shifting our focus to the points we wish to discuss, we advance a few qualifications to Garegnani’s approach to the prelectures. To start with, we would stress that the content of Sraffa’s 1925 and 1926 articles and of the prelectures (manuscript D3/12/3 [A4]) suggest that at that time—even though he had directed his critique almost exclusively against contemporary economists—Sraffa’s knowledge of the classical authors and of Marx was comparable to his knowledge of more recent literature.⁷ Secondly, we would say that, until a number of questions are addressed, we cannot take for granted that the structure of the prelectures closely reflects the evolution of Sraffa’s thought in the sum­mer of 1927. Indeed, it should be considered whether that manuscript, as we know it, might be better described as reflecting an arrangement intentionally designed by Sraffa to suit didactical purposes. Furthermore, it must be noted that only six out of more than eighty sheets that form the prelectures (Sraffa Papers, D3/12/3/1-7 [A4/2-A4∕4iii]) had been numbered by Sraffa himself.⁸ This fact is particularly important if we want to assess the relationship between the order of the sheets that we now may observe and the order in which they had been written, or the likelihood that some parts of the prelec­tures may have been removed by Sraffa himself to different folders and are now kept in other sections of the Sraffa Papers. Finally, it should also be considered whether other manuscripts in the Sraffa Papers could have been written in the same period (i.e., in the summer of 1927).

Be that as it may, our present focus is not directed toward Garegnani’s approach to the general structure of the prelectures. We rather focus on the part of Garegnani’s interpretation dealing with the more specific question of pointing out the spring, if we may say so, that may have led Sraffa to write the earliest formulation of his equations.

Our analysis begins with detailed consideration of a part of the prelectures that, according to Garegnani, marks the onset of Sraffa’s new understanding of the classi­cal approach (Garegnani, 2005, 464; see also 461-63) and, pointing to the possibility of reducing all inputs of a given production process to what Sraffa called an absolutely necessary commodity, identifies a line that he would have followed in his subsequent research up to the earliest formulation of his equations (Garegnani, 2005, 465). With regard to this document, we argue that it contains additional information (not mentioned by Garegnani) that is crucial to understanding the origins of Sraffa’s equations (sec­tion 2). Furthermore, we show that the manuscript that, according to Garegnani, would reflect the steps that in November 1927 would have led Sraffa precisely to his equations, are susceptible to a different interpretation (section 3). A short digression allows us to consider the grounds that may support the hypothesis that it was exactly toward the end of November 1927 that Sraffa wrote the earliest formulations of his equations (section 4). Finally, we point to other manuscripts that may more closely reflect Sraffa’s transition from the prelectures and from the conception of an absolutely necessary commodity to his equations (section 5).

2.