Clearly, information is of the utmost importance in making economic decisions, especially when it comes to securities or other assets whose value dep… - Kenneth Arrow

As is by now well known, attempts to form social judgments by aggregating individual expressed preferences always lead to the possibility of paradox.

In fact, is is not a mere empirical accident that not all the contingent markets needed for efficiency exist but a necessary fact with deep implications for the workings and structure of economic institutions. Roughly speaking, information about particular events, even after they have occurred, is not spread evenly throughout the population. Two people cannot enter into a contract contingent on the occurrence of a certain event or state if only one of them in fact will know that the event has occurred. A particular example of this is sometimes known as “moral hazard” in the insurance and economic literature. The very existence of insurance will change individual behavior in the direction of less care in avoiding risks.

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.