V the Ideal Output in a One-firm Industry

§ 21. In a one-firm industry when and the supply price of an output y is, therefore, the analysis of the preceding discussion is applicable, the formal expression of it needing to be modified only so far as to provide for the identity of xr and y. In a one-firm industry, in which marginal cost exceeds average cost, something different is needed. The marginal supply price to the industry and the supply price are both equal to F'(y). Therefore, if no transfer elements are involved, so that the marginal supply price to the industry is equal to the marginal supply price to the community, and output equating supply price and demand price—which, in this case, is the output proper alike to simple competition and to discriminating monopoly of the first degree—will be equal to the ideal output, in spite of the fact that the industry conforms to the law of increasing supply price. This case in general can only occur when imported ingredients of increasing supply price are being used. If transfer elements are involved, an output which equates supply price and demand price will be less than the ideal output.