Supply and demand determine the prices of the productive services
The solution is simple. The prices of the productive services are determined by supply and demand. This demand is indirect however: “when a good is in demand, all the services susceptible to produce it are in demand” (Say 1828 [2010]: 705).
Their supplies may depend on different causes. Say, for example, explains that the supply of services by entrepreneurs is limited because of the moral qualities necessary to this kind of labour, the necessity of having a sufficient capital and the uncertainty of the gains in this activity.The phrase “natural wage” does not appear in Say’s works. He admits, however, that “it is difficult that the price of labour of the simple worker rises above or falls below the rate needed to maintain the number of this class of workers at the required level” (ibid.:735). Sismondi (1819, vol. 1: 89) put forward a similar idea. However, this necessary rate does not play the same role as that of the natural rate in Smith and Ricardo’s analyses as it only determines the price of a particular category of labour.
Say takes up Smith’s idea: rent is a monopoly income. “Land... is not the only natural resource which has productive power but is the only one man could own and consequently, from which he could appropriate the benefits” (Say 1803 [2006]: 793). He thus opposed economists who, like Ricardo and Destutt de Tracy, consider rent as a differential income, which is not a component of the price of commodities. He disagrees with the idea that marginal land does not yield any rent: any cultivated land necessarily yields a rent because no owner would ever allow the cultivation of his land for nothing.