1. _The economist should view money cost as an intermediate and not as an ultimate explanation of value._ The value of all things must be traced back to gratification, to the relation of goods with psychic income. This being true, the value of the factors which the enterpriser uses must be derived from the value of the products, and not the reverse. This does not mean that the business man is deceived into the belief that he has in cost of production a final explanation of value. He simply is not interested in that question. He knows that there are many influences determining the cost of the factors he buys, but they are distant; he cannot influence them, and in the single stage of his production they seem to fix the price. In some purchases, and on the stock exchange, a marvelous recognition and analysis of the most distant influences is necessary; but in general a superficial view of value is taken in business; it does not pay to do other. The logical treatment, however, must go deeper into the question and trace the cost of agents back to the ultimate cause of value, that is, to want-gratifying power. To say that the price of a product is determined by the money cost, or price, of the factors is simply to postpone the answer to the question of value; one has still to ask, What determines the money cost, or price, of those factors themselves? [Sidenote: The cost of agents is fixed by their marginal utility in alternative uses] 2. _The demand for any factor entering into products is reflected, in an increased price, to its cost in all competing products._ Figuratively speaking, products compete with each other for the factors that enter into them. According to location, quality of the soil, and improvements, a certain area of land has various rival uses. These uses bid for the land, or put in an economic claim for it. Products of a higher value outbid and exclude those of a lower. If fine wine can be raised on a piece of land, potatoes ordinarily will not be planted in it. But if there is such a supply of that quality of land that it continues to be used side by side for both products, it will have the same value and yield the same rental in both uses. The least utility yielded by any portion of the supply fixes the value of all the units. Machines are usually made for some product determined in advance, but often they are only partially specialized and within limits they can be adapted. Sewing-machine factories were readily turned to the making of bicycles at the time of greatest demand, and bicycle factories later were used for the making of automobiles. Thus, in general, machinery is used for the product to which it contributes the most value. Any enterpriser seeking it for any other use finds its "cost" affected by its various alternative uses. The same is true of all the materials and of all the grades of labor entering into products. The enterpriser's _cost_ is therefore the reflection of the want-gratifying power of the productive