We develop a belief-based account of decision under uncertainty. This model predicts decisions under uncertainty from (i) judgments of probability, which are assumed to satisfy support theory; and (ii) decisions under risk, which are assumed to satisfy prospect theory. In two experiments,...

We argue that people intuitively distinguish epistemic (knowable) uncertainty from aleatory (random) uncertainty and show that the relative salience of these dimensions is reflected in natural language use. We hypothesize that confidence statements (e.g., “I am fairly confident,” “I am 90%...

People view uncertain events as knowable in principle (epistemic uncertainty), as fundamentally random (aleatory uncertainty), or as some mixture of the two. We show that people make more extreme probability judgments (i.e., closer to 0 or 1) for events they view as entailing more epistemic...

In nine studies, we find that investors intuitively distinguish two independent dimensions of uncertainty: epistemic uncertainty that they attribute to missing knowledge, skill, or information, versus aleatory uncertainty that they attribute to chance or stochastic processes. Investors who view...