If markets were sufficiently complete, with all futures periods and all uncertain contingencies already provided for in the contracts, the concept of… - Kenneth Arrow

Speaking very broadly, almost any human action involves choice; the external environment delimits a range of possible actions at any given moment but does not usually reduce that range to a single alternative. The formulation of a theory of human action in some sphere as a theory of choice means its presentation as a functional relation associating with each possible range of alternatives a chosen one among them.

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.

The slippery role of information as an economic good is of deep significance to economic behavior, especially in the relatively information-rich modern economy. It is an economic good in the traditional sense; it is valuable, and it is costly. But it has a peculiar algebra. Adding one ton of steel to another permits more to be done; repeating the same item of information does not add anything useful. On the other hand, supplying a ton of steel to another reduces the steel available to the supplier; supplying information to another does not reduce the information available to the supplier.