The anatomy of ignorance Diagnoses from literature

Ignorance represents a situation in which some potential outcomes are not even identified. Often they are both unknown and unknowable (Gomory, 1995; Zeckhauser, 2006). On a continuum that begins with risk and progresses through uncertainty, ignorance is the third, final, and most extreme state in the sequence. With risk and uncertainty, the possible future states of the world are known. With risk, their probabilities are known as well; with uncertainty their probabilities are unknown. A roll of two dice involves risk; a prediction about the stock market a year hence involves uncertainty. The well-developed discipline of decision analysis prescribes how to make decisions when confronted with either risk or uncertainty. One of its central prescriptions is to start by assigning probabilities—objective if risk, subjective if uncertainty—to the alternative future states of the world. But with ignorance, where those states are not even identified, attaching probabilities is clearly impossible. Note, these states are not extreme outliers on some understood spectrum; they are outcomes that the decision maker fails to even conjecture. Our title, “The Anatomy of Ignorance,” introduces a medical metaphor. Our analysis diagnoses ignorance as a malady that inflicts significant damages at the individual and societal levels. Fortunately, as with many maladies, understanding ignorance can help us recognize its presence and treat it more effectively.