Not only is it possible to devise complete models of the economy on hypotheses other than rationality, but in fact virtually every practical theory o… - Kenneth Arrow

The comparative economic efficiency of capitalism and socialism remains one of the most controversial areas. The classical socialist argument is that the anarchy of production under capitalism leads to great wastage. An appeal to the virtues of the price system is, in fact, only a partial answer to this critique. The central argument, which implies the efficiency of a competitive economic system, presupposes that all relevant goods are available at prices that are the same for all participants and that supplies and demands of all goods balance. Now virtually all economic decisions have implications for supplies and demands on future markets. The concept of capital, the very root of the term “capitalism,” refers to the setting-aside of resources for use in future production and sale. Hence, goods to be produced in the future are effectively economic commodities today. For efficient resource allocation, the prices of future goods should be known today. But they are not. Markets for current goods exist and enable a certain coherence between supply and demand there. But very few such markets exist for delivery of goods in the future. Hence, plans made by different agents may be based on inconsistent assumptions about the future. Investment plans may be excessive or inadequate to meet future demands or to employ the future labor force.

The forces of competition and the tendency to profit-maximization operate to mitigate these differences. However, the basic fact of a personnel investment prevents these counteracting tendencies from working with full force. In the end, we remain with wage differences coupled with tendencies to segregation.

I want, however, to conclude by calling attention to a less visible form of social action: norms of social behavior, including ethical and moral codes. I suggest as one possible interpretation that they are reactions of society to compensate for market failures. It is useful for individuals to have some trust in each other's word. In the absence of trust it would become very costly to arrange for alternative sanctions and guarantees, and many opportunities for mutually beneficial cooperation would have to be, foregone.