ABSTRACT
This chapter deals with Sraffa’s early work on joint production. Sraffa had studied cases of joint production as early as the late 1920s within a Marshallian framework of supply and demand. Marshall had argued that in the case of two products produced jointly by means of a single process of production there was only one price equation to determine two prices. A relative demand function was taken to provide the needed extra equation in order to ascertain relative prices. Did the case of joint production imply that the physical real cost approach to the problem of value, which Sraffa had elaborated in the late 1920s, was unable to cope with the problem at hand and that subjective elements expressed in demand functions had to be introduced? Sraffa responded to the challenge by pointing out that requirements for use of the various commodities could be met by operating simultaneously several joint production processes that used or produced the joint products in different proportions. While Sraffa managed to establish important results as early as 1942, including for example, the possibility of negative labour values vis-à-vis strictly positive prices, others had to wait until the second half of the 1950s.
