Uncertainty--doubt about what is or could be--fuels our ambitions and fears. Tantalizing possibilities spur us to innovate and explore. Yet, we also strive to reduce uncertainty. Mountain climbers and deep-sea divers plan carefully. Rules, routines, and research in business, the law, and medicine are designed to increase predictability and forestall unpleasant surprises. Mainstream economics, however, hides from uncertainty, banishing it to the mystical...