Evaluate the role of money (or its absence) in conveying knowledge in both the planned economy Marx describes and in a market-driven system.  Is Mises and Hayek’s criticism, the “knowledge problem,” a valid one, or does Marx have a better solution than Hayek and Mises understand?
Mises again: “In an exchange economy, the objective exchange value of commodities becomes the unit of calculation. This involves a threefold advantage. In the first place we are able to take as the basis of calculation the valuation of all individuals participating in trade. The subjective valuation of one individual is not directly comparable with the subjective valuation of others. It only becomes so as an exchange value arising from the interplay of the subjective valuations of all who take part in buying and selling. Secondly, calculations of this sort provide a control upon the appropriate use of the means of production. They enable those who desire to calculate the cost of complicated processes of production to see at once whether they are working as economically as others. If, under prevailing market prices, they cannot carry through the process at a profit, it is a clear proof that others are better able to turn to good account the instrumental goods in question. Finally, calculations based upon exchange values enable us to reduce values to a common unit. And since the higgling of the market establishes substitution relations between commodities, any commodity desired can be chosen for this purpose. In a money economy, money is the commodity chosen.”