Sulla trattazione del capitale negli economisti marginalisti: il capitale come grandezza singola in alcuni scritti dei primi anni trenta

The aim of this paper is to call attention on some writings of the early 1930s by D.H. Robertson and J.R. Hicks. These writings present, with a clarity not easily found elsewhere, the two reasons why marginalist economist, who till the last three decades normally treated capital as a single magnitude, were in fact compelled to do so: the fact that only this treatment could lend plausibility to the notion of substitutability between factors of production; and the fact that a different treatment would have made it impossible to include capital among the data of the theory and at the same time to determine a “normal position” of the economic system. As is well known, the notion of capital as a single magnitude has been shown to be untenable during the controversies on capital theory of the 1960s and has consequently been abandoned by orthodox theory. But the implications of this shift in pure theory have not been widely appreciated and it is hoped that looking at the question from an historical point of view might bring some help in clarifying it.