"You think that needs explaining," he added, as I looked incredulous, "but the explanation need not be long; the cost of the labor which produced it was recognized as the legitimate basis of the price of an article in your day, and so it is in ours.

In your day, it was the difference in wages that made the difference in the cost of labor; now it is the relative number of hours constituting a day's work in different trades, the maintenance of the worker being equal in all cases.

The cost of a man's work in a trade so difficult that in order to attract volunteers the hours have to be fixed at four a day is twice as great as that in a trade where the men work eight hours.

The result as to the cost of labor, you see, is just the same as if the man working four hours were paid, under your system, twice the wages the others get.

This calculation applied to the labor employed in the various processes of a manufactured article gives its price relatively to other articles.
Besides the cost of production and transportation, the factor of scarcity affects the prices of some commodities.