Collective ambiguity attitude as response to individuals’ ones and belief disagreements

This paper axiomatically characterizes the rule of aggregating individuals’ ambiguous beliefs into the society’s ambiguous belief. We consider a family of social rankings over acts which are indexed by pairs of utility profiles and ambiguous belief profiles, and impose variable-profile axioms which express how society should respond to changes in belief profiles and changes in how beliefs disagree. Our characterization allows two kinds of collective ambiguity aversion, one arising due to individuals’ ambiguity aversion and the other arising due to disagreements in beliefs.