Praxeology can never furnish an ultimate explanation for a man’s time preferences. These are psychologically determined by each person and must therefore be taken, in the final analysis, as data by economists. However, praxeological analysis can supply some truths about time preferences, using ceteris paribus assumptions. Thus, as we have seen above, each person has a time-preference schedule relating to his money stock.

It is clear that the natural interest rates are highly flexible; they tend toward uniformity and are easily changed as entrepreneurial expectations change. In the real world the prices of the various factors and intermediate products, as well as of the final products, are subject to continual fluctuation, as are the prices of stock and the interest return on them. It is also clear that the interest rate on short-term loans is easily changed with changed conditions. As the natural interest rate changes, the new loans for short periods can easily conform to the change.

The late Professor Joseph Schumpeter pioneered a theory of interest which holds that the rate of interest will be zero in the evenly rotating economy. It should be clear from the above discussion why the rate of interest (the pure rate of interest in the ERE) could never be zero. It is determined by individual time preferences, which are all positive. To maintain his position, Schumpeter was forced to assert, as does Frank Knight, that capital maintains itself permanently in the ERE.

The time market, like other markets, consists of component individuals whose schedules are aggregated to form the market supply and demand schedules. The intricacy of the time market (and of the money market as well) consists in the fact that it is also divided and subdivided into various distinguishable sub-markets. These are aggregable into a total market, but the subsidiary components are interesting and highly significant in their own right and deserve further analysis. They themselves, of course, are composed of individual supply and demand schedules.

Before considering the component parts of the time market further, let us go to the very root of the matter: the value scale of the individual. As we have seen in the problem of pricing and demand, the individual’s value scale provides the key to the determination of all events on the market. This is no less true in regard to the interest rate. Here the key is the schedule of time-preference valuations of the individual.

UP TO THIS POINT WE HAVE1 been treating the structure of production as amalgamated into one stage. One or several firms have all been vertically integrating all the stages of production of a product (with all factors specific), until finally the product is sold to the consumer. This is certainly an unrealistic assumption.