I. INTRODUCTION

The economic literature of the seventies shows a remarkable mathematical development of Marxian economics, especially after the publication, in 1970 and 1973 respectively, of Brody’s and Morishima books on Marx’s theory of value and growth (Brody (1970), Morishima (1973)) (it thus apparently took an entire decade for the many fruits contained in Sraffa’s Production of Commodities by Means of Commodities, in Okisio’s work (Okisio (1963)) and in the pioneering Econometrica paper of Morishima and Seton (1961) to mature). Not surprisingly, the relative abundance of mathematical papers and notes on the labour theory of value was accompanied by a lot of controversy. Steedman (1975) for instance, pointed out that joint production, when expressed in a linear system of equations, might easily give rise to negative labour values, a phenomenon already met by Morishima ((1973), pp. 182 ff.). In that case, positive surplus value is neither a necessary nor a sufficient condition for the existence of positive profits. Such apparent perversities and the need of introducing the concept of scrapping unprofitable capital goods and technology, lead Morishima to develop his inequality approach.