A Pictorial Approach to the Standard Commodity with a Digression

Abstract

If we wish to depict an economy, we need as many dimensions as the commodities that inhabit it. An economy in which only one commodity is produced and consumed is the simplest possible one and its picture, being one-dimensional, is represented by a straight line.

But the whole point of these schemes is to give a picture, not a quick method of calculation (Piero Sraffa, 1942)

First then, suppose there be in a Territory a thousand people, let these people be supposed sufficient to Till this whole Territory as to the Husbandry of Corn, which we will suppose to contain all necessaries of life, as in the Lords Prayer we suppose the word Bread doth. (William Petty, 1662; quoted by Marshall, 1907; quoted by Sraffa, 1925)