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...

We compare Bayesian with the two non-Bayesian updating under ambiguity in its model specification and numerical implications. For an ambiguity averse (seeking) decision maker, we find that Gilboa and Schmeidler (GS) updating leads to a lower (higher) certainty equivalent (CE) than...