Joint production: Triumph of economic over mathematical logic?*

Sraffa's book artfully combines an exposition of key problems of capital theory, using economic logic, with mathematical arguments, and he created a school of disciples extending his ideas by means of both methods. His analysis of single product systems has turned out essentially to be flawless, but the problems of joint production cannot simply be solved on the basis of analogies with single production. A truncation approach and a dynamic approach are discussed in order to summarise his main results, to illustrate his method and to take stock of the recent developments of the theory.