The essential fact of life—for regulation as well as for antitrust—is that data about the past, predictions about the future, and judgments about anything are not always extant, costless, reasonably obtainable, or very reliable. Furthermore, decision-makers everywhere are of mixed quality and sometimes of no quality at all.
Phillip Areeda, "Antitrust Laws and Public Utility Regulation," The Bell Journal of Economics and Management Science (Spring 1972)