It is clear that the rate of interest plays a crucial role in the system of production in the complex, monetary economy.7 How is the rate of interest determined?

At this point, let us reintroduce the concept of “cost” into the analysis. We have seen above that the cost, or “marginal” cost, of any decision is the next highest utility that must be forgone because of the decision. When a means M must be distributed among ends E1, E2, and E3, with E1 ranked highest on the individual’s value scale, the individual attempts to allocate the means so as to attain his most highly valued ends and to forgo those ranked lower, although he will attain as many of his ends as he can with the means available.

Up to this point we have discussed the case in which the owners of land and labor, i.e., of the original factors, restrict their possible consumption and invest their factors in a production process, which, after a certain time, produces a consumers’ good to be sold to consumers for money. Now let us consider a situation in which the owners of the factors do not own the final product. How could this come about? Let us first forget about the various stages of the production process and assume for the moment that all the stages can be lumped together as one.

We are deferring until later the major part of the analysis of the pricing of productive services and factors. At this point we can see, however, that the purchasing of labor and land services are directly analogous. The classical discussion of productive income treats labor as earning wages whereas land earns rents, and the two are supposed to be subject to completely different laws. Actually, however, the earnings of labor and land services are analogous.

In the ERE, therefore, every good sold to consumers will sell at a certain “final equilibrium” price and at certain total sales. These receipts will accrue in part to capitalists in the form of interest income, and the remainder to owners of land and labor. The payments of income to the producers have also been popularly termed “costs.” These are clearly money costs, or money expenses, and obviously are not the same thing as “costs” in the psychic sense of subjective opportunity forgone.

We have seen that, for all goods, total receipts to sellers will tend to equal total payments to factors, and this equality will be established in the evenly rotating economy. In the ERE, interest income will be earned at the same uniform rate by capitalists throughout the economy. The remainder of income from production and sale to consumers will be earned by the owners of the original factors: land and labor.

THE ANALYSIS OF PRODUCTION ACTIVITIES—the actions that eventually result in the attainment of consumers’ goods—is a highly intricate one for a complex, monetary market economy. It is best, therefore, to summarize now some of the most applicable of the fundamental principles formulated in chapter 1. In that chapter we applied those principles to a Crusoe economy only. Actually, however, they are applicable to any type of economy and are the indispensable keys to the analysis of the complex modern economy. Some of these fundamental principles are:

Analysis of the activities of production in a monetary market economy is a highly complex matter. An explanation of these activities, in particular the determination of prices and therefore the return to factors, the allocation of factors, and the formation of capital, can be developed only if we use the mental construction of the evenly rotating economy.

Crucial to understanding the process of production is the question of the specificity of factors, a problem we touched on in chapter 1. A specific factor is one suitable to the production of only one product. A purely nonspecific factor would be one equally suited to the production of all possible products. It is clear that not all factors could be purely nonspecific, for in that case all factors would be purely interchangeable, i.e., there would be need for only one factor. But we have seen that human action implies more than one existing factor.