COMMUNICATION 61 one time into the value of the product in the manufacture of which they are consumed, while the elements of fixed capital transfer their value to the product only gradually in proportion to their wear and tear. It follows that the price of the product is influenced far more by the price of raw materials than by that of fixed capital, although the rate of profit is determined by the total value of capital applied no matter how much of it is consumed in the making of the product. But it is evident—although we merely mention it in passing since we siill assume that commodities are sold at their values, so that price fluctuations caused by competition do not as yet concern us—that the expansion or contraction of the market depends on the price of the individual commodity and is inversely proportional to the rise or fall of this price. It actually develops, therefore, that the price of the product does not rise in proportion to that of the raw material, and that it docs not fall in proportion to that of raw material. Consequently, the rate of profit falh lower in one instance, and rises higher in the other than would have been the case if the products were sold at thdir value.7 This rather lengthy quotation was necessary only in order to show that Marx was fully aware of the problems connected with the effects of changes in the prices of the elements of constant capital and of changes in market conditions of competition (of supply and demand) on the price of the product and on the rate of profit. Marx also devotes a separate chapter on the "Effects of Changes in Wages". It must nevertheless be admitted that Piero Sraffa's treatment of the subject is very much more exhaustive and satisfactory. His analysis of the problem of the transformation of values into prices has undoubtedly added a new dimension to the subject and has made Marxian economics richer and logically acceptable. Ix has rudely shaken the pillars of the neoclassical edifice and even ofKeynesian work. The reswitching debate in 1966 mirrors this debacle in all its fullness. Real Wages Joan Robinson is, however, mainly concerned with the evolution of wages in terms of commodities as capitalism develops. In this connection too she tries to expose an alleged discrepancy between Volumes I and III of Capital. According to her, Marx in Volume I states that commodity wages will have a tendency "to remain constant over the future.95 In Volume III, on the other hand, Marx assumes that "the rate of exploitation tends to remain constant over a long future". However, since productivity increases, a constant rate of exploitation would ensure a rise in commodity wages. Therefore, it is argued, there is a contra diction between Volume I and Volume III. It is in discussing the determination of the value of labour power in Volume I that Marx refers to this subject: His (labouring individual's) natural wants such as food, clothing, fuel