The Role of Panels in Enhancing Legal Predictability

This article considers the justification for using panels of judges to make decisions in common law systems. The usual argument is that panels are more likely than lone judges to make correct judgments. This article suggests an additional justification: panels increase the predictability of law, so that potential litigants can anticipate correctly which legal rules will apply in their cases. Three models, each with a different conception of the legal process and the role of precedent, are employed to demonstrate the predictability-enhancing effect of panels. This effect is strongest when precedent has a substantial impact on how judges make decisions. A prominent feature of many legal systems is the existence of courts — particularly at the appellate level — in which panels of judges make decisions. The justification for using a panel of judges rather than a lone judge seems obvious: a panel is more likely than a single judge to make a correct decision, where “correct” is understood to mean the dominant opinion in the legal community. This is true because the majority opinion of a group of judges is more likely than the opinion of a single judge to match the majority opinion of the larger population from which the judges are drawn — an insight widely known as the Condorcet jury theorem. Error correction is by far the most common argument in favor of having appellate courts, and the existence of multi-judge panels apparently adds to the perception that such courts are more likely to be trustworthy. As Judith Reznik (1984, 856) notes, “Appellate judges also lay claim to correctness through their numbers. ... Typically, the second [i.e., appellate level] judgment is a collective one, in which at least two appellate judges join. The intuition is that two thinkers are less likely to render poor decisions than is one.” Of course, the judgment of what constitutes a poor decision has much to do with prevailing opinions in the legal community as a whole. Steven Shavell (1995) has made the error correction argument more precise, arguing that an appeals process can harness information litigants have about the correctness of decisions