Experimental results on the Ellsberg paradox typically reveal behavior that is commonly interpreted as ambiguity aversion. The experiments reported in the current paper find the objective probabilities for drawing a red ball that make subjects indifferent between various risky and uncertain...

We use probability-matching variations on Ellsberg’s single-urn experiment to assess three questions: (1) How sensitive are ambiguity attitudes to changes from a gain to a loss frame? (2) How sensitive are ambiguity attitudes to making ambiguity easier to recognize? (3) What is the relation...

Progress toward universal health coverage (UHC) requires making difficult trade-offs. In this journal, Dr. Margaret Chan, the World Health Organization (WHO) Director-General, has endorsed the principles for making such decisions put forward by the WHO Consultative Group on Equity and UHC. These...