A Model of Expertise

We study a model in which two perfectly informed experts offer advice to a decision maker whose actions affect the welfare of all. Experts are biased and thus may wish to pull the decision maker in different directions and to different degrees. When the decision maker consults only a single expert, the expert withholds substantial information from the decision maker. We ask whether this situation is improved by having the decision maker consult a cabinet of (two) experts. We first show that there is no perfect Bayesian equilibrium direction, it is never beneficial to consult both. In contrast, when experts are biased in opposite directions, it is always beneficial to consult both. Finally, a cabinet of extremists is of no value.