We consider a decision maker who is unaware of objects to be sampled and thus cannot form beliefs about the occurrence of particular objects. Ex ante she can form beliefs about the occurrence of novelty and the frequencies of yet to be known objects. Conditional on any sampled objects, she can...

This paper proposes that the ambiguity reflected by a set of priors remains unchanged when the set is translated within the probability simplex, i.e. ambiguity is location invariant. This unifies and generalises numerous influential definitions of ambiguity in the literature. Location invariance...

We study business uncertainty in high- versus low-volatility environments by surveying over 31,000 managers across 41 countries. We elicit subjective probability distributions for future own-firm sales and measure firm-level uncertainty with their mean absolute deviations. Analogously, we...