The Judicial Expert in a Two-Tier Hierarchy

We study how the presence of biased expertise influences judicial decision-making. When an appeals-court judge's decision depends only on the information he gets about the expertise proceedings, a perfectly separating equilibrium may arise in which the losing litigant appeals only if the trial-court judge's decision is incorrect. Surprisingly enough, an increase in the probability that the expertise is biased and a decrease in the level of scrutiny of the appeals court may be beneficial. When the appeals-court judge uses a Bayesian mechanism to make his decision, a perfectly separating equilibrium never exists.