In most medical decisions probabilities are ambiguous and not objectively known. Empirical evidence suggests that people's preferences are affected by ambiguity. Health economic analyses generally ignore ambiguity preferences and assume that they are the same as preferences under risk. We show...

Do physicians behave rationally when facing a new disease? This study assesses physicians’ ambiguity attitudes towards the COVID-19 pandemic at its early breakout and the stock market using a revealed preference approach. We find that physicians exhibit significant deviation from expected...

Do physicians behave rationally when facing a new disease? This study assesses physicians’ ambiguity attitudes towards the COVID-19 pandemic at its early breakout and the stock market using a revealed preference approach. We find that physicians exhibit significant deviation from expected...

Experiments on intertemporal consumption typically show that people have difficulties in optimally solving such problems. Previous studies have focused on contexts in which agents are faced with risky future incomes and have to plan over long horizons. We present an experiment comparing decision...

In many consulting environments, the expert often assertively recommends the client to take an action but is vague about the probability of that action’s outcomes, making the recommendation ambiguous. This paper analytically investigates this phenomenon by incorporating the client’s optimism...

We propose and axiomatically characterize dynamically consistent update rules for decision making under ambiguity. These rules apply to the preferences with multiple priors of Gilboa and Schmeidler (1989), and are the first, for any model of preferences over acts, to be able to reconcile typical...

Current decision-making models assume that an individual's attitude towards risk does not vary across different sources. A decision maker's processing of known probabilities and the resulting degree of probability weighting should therefore be unique. This paper provides evidence that challenges...

This paper studies sequential information acquisition by an ambiguity-averse decision maker (DM), who decides how long to collect information before taking an irreversible action. The agent optimizes against the worst-case belief and updates prior by prior. We show that the consideration of...

Observed individual behavior in the presence of ambiguity is characterized by insufficient responsiveness to changes in subjective likelihoods. Such likelihood insensitivity under ambiguity is integral to theoretical models and predictive of behavior in many important domains such as financial...

Before choosing her action to match the state of the world, an agent observes a stream of messages generated by some unknown binary signal. The agent can either learn the underlying signal for free and update her belief accordingly or ignore the observed message and keep her prior belief. After...