Considering now the reaction of the value of production goods on the value of particular products, we may represent the more complex case, corresponding to real life, by supposing products A, B and C to be made from production goods P and Q, P and R, and P and S respectively. In this case the products are cognate only by reason of their relationship through P. The production goods Q, R and S are not common. Here as before the supplies and values of the products A, B and C are in a relation of mutual dependence. The dependence is, however, not so close as in the first artificially simplified case considered above. In the present case it is not the values of A, B and C themselves which are brought to an equilibrium, but it is merely the _productive contributions of P_ in the values of A, B and C that must reach an equality. If a unit of P obtains a higher productive contribution in A than in B and C, more P will be put to the making of A’s and less to the making of B’s and C’s, until a unit of P attains the same productive contribution in each of these products. If the amount of P put to the making of A’s is increased, the supply of A’s will be increased and A’s will decline in value. But the decline in the value of A’s caused in this manner will fall entirely upon the productive contribution of P. The decline of value takes place merely to bring the contribution of P’s in A’s to an equilibrium with the contribution of P’s in B and C. Abstract as the foregoing formulæ are, they are nevertheless real. If entrepreneurs were not able to ascertain, at least approximately, the productive contributions of the various production goods entering into the product which they manufacture, they would be unable to tell either how much of each productive factor they can afford to buy or what price they can pay for it. When we call to mind the fact that in actual industry most production goods are themselves products, and that into the majority of final products nearly all the great common production goods enter, we realize the stupendous complexity of the relationships of cognate products in actual life. It is no wonder that ordinarily a whole half of the process by which the values of all these fellow products are brought to mutual adjustment escapes our notice. Pig iron derives its value from a thousand and one kinds of products. When the value of one of these alone is being brought into adjustment with the value of pig iron, the mass is all on the side of the pig iron, if we may so express it. In this movement the single product is seeking a value-equilibrium with all the vast multitude of other products of pig-iron. It seems itself to effect all the adjusting. As a matter of fact, it contributes its due share to the determination of the value of the raw iron. Thus far, we may safely affirm, the difficulty which, at first sight, the law of entrepreneur’s cost seems to present to the utility theory has been quite surmounted.