Structured Ambiguity and Sequential Aggregation

Overview & Synopsis

When society notices the possibility for individual priors to be misspecified, it faces a structured ambiguity while trying to make a collective decision. Here, we highlight the different principles allowing to overcome such a structured ambiguity by relying on the consensual core of individual priors. This is done through a sequential aggregation mechanism. The decision problem at stake is decomposed into several steps and aggregation is made progressively. Compared to standard synchronized aggregation, the possibilities of aggregation are then shown to dramatically increase.