Investment Decision-Making Under Uncertainty
In a deterministic world, investing would be an exercise in pure arithmetic. However, the global markets operate in a state of perpetual flux where "risk" and "uncertainty" are often conflated but fundamentally different. For the sophisticated practitioner, researcher, or student, mastering the distinction is the first step toward achieving alpha. 1. The Nature of Uncertainty in Modern Finance Investment decision-making has evolved from risk-based frameworks (where probabilities are known) to uncertainty-based paradigms (where probabilities are ambiguous or unknowable). This distinction, first formalized by Frank Knight, remains central to modern financial thinking. The Knightian Distinction: Risk vs. Uncertainty To analyse investment decisions, we must first adopt the framework established by economist Frank Knight: Risk: Situations where the outcomes are unknown, but the probability distribution of those outcomes is known (e.g., a spi...