Conclusions

In this chapter we have examined the evidence put forward by Pierangelo Garegnani to support his thesis that Sraffa came to conceive his equations within a process started from the recognition that a conception of physical real cost was at the root of the classi­cal economists’ approach to value.

We have argued that this contention has solid foundations, but that some of its parts may be significantly enriched, while others need deep revision. More precisely, our analy­sis has developed three main points: ^{1 2 3}

1. We have shown that the text of the manuscript dating from the summer of 1927 and dubbed by Garegnani prelectures reveals a deeper and stronger relationship to Sraffa’s earliest formulations of his equations (in particular, of his “first equa­tions”) than suggested by Garegnani himself. This relationship rests on the fact that identifying the case of an economy that produces no surplus is a significant part of the analysis of the reduction to an absolutely necessary commodity developed in the prelectures and on the fact that the description of production processes and of bundles of commodities that we can find in that part of the prelectures is very close to what we can find in Sraffa’s earliest formulations of his equations.

2. We have argued that the document that, according to Garegnani, illustrates the moment when Sraffa again took up (in November 1927) the concept of absolutely necessary commodity and the way it led him to write his equations is more likely to reflect a slightly subsequent stage in the development of Sraffa’s work and does not necessarily refer to a reduction to an absolutely necessary commodity.

3.

If we compare the results on value determination achieved by Sraffa in late November 1927 to the stage his analysis of physical real cost had reached in the summer of 1927, we may see that, in a single stroke, he had solved, or wiped away, at least four problems that had been stressed in the prelectures. First, individual values, or prices, did not have to rely on other individual values to be taken as already known, leading to circular rea­soning. Second, no absolutely necessary commodity had to be singled out or defined. Third, by representing economic activity through a sort of photographic picture, to turn to a metaphor already used by Roncaglia in his 1975 book, where outputs and inputs (including workers’ consumption, which had been substituted for their labor time) were taken as given, the question of the existence of substitutes was also eliminated. Fourth, no hypothesis as to an ultimate cause or common measure of value had to be introduced. The overall result, as Sraffa later put it, was that “the equations show that the conditions of exchange are entirely determined by the conditions of production” (D3/12/7/87 [A7∕29iii]).