Various medical groups are continually putting out advice as to health-inducing behavior (diet, exercise, and so forth). Individuals who follow this … - Kenneth Arrow

Finding out the prices of a large range of commodities is itself a costly enterprise, and knowledge of this fact by price setters is itself enough to create incentives for inefficient market behavior. If one individual has more information about the quality of a good than the second, the first may exploit the situation, and the second, distrusting him, may not take advantage of what is in fact a desirable trade.

I interpret moral obligation as the carrying out of agreements which may, however, be implicit. Thus, a society in which everyone immediately executed his aggressive impulses would be untenable. Therefore, there is an agreement that I will refrain from aggressive actions, which in themselves give me satisfaction, in return for your not taking aggressive action against me. However, conscious agreements to achieve these ends are much too costly in terms of information and bargaining. Therefore, as societies have evolved they have found it economical to make these agreements at an unconscious, implicit level. Internalized feelings of guilt and right are essentially unconscious equivalents of agreements that represent social decisions.

From a theoretical viewpoint, one might say that the market is in a strange sort of equilibrium; there is some shadowy sort of price at which supply and demand are equated at zero. But this price is not performing much of a signaling function.