A decision maker needs predictions about the realization of a repeated experiment in each period. An expert provides a theory that, conditional on each finite history of outcomes, supplies a probabilistic prediction about the next outcome. However, there may be false experts without any...

A planner wants to elicit information about an agent's preference relation, but not the entire ordering. Specifically, preferences are grouped into "types", and the planner only wants to elicit the agent's type. We first assume beliefs about randomization are subjective, and show that a space of...