Constructing legal rules on appellate courts

Appellate courts make policy, not only by hearing cases themselves, but by establishing legal rules for the disposition of future cases. The problem is that such courts are generally multimember, or collegial, courts. If different judges prefer different rules, can a collegial court establish meaningful legal rules? Can preferences that take the form of legal rules be aggregated? I use a "case-space" model to show that there will exist a collegial rule that captures majoritarian preferences, and to show that there will exist a median rule even if there is no single median judge. I show how collegial rules can differ from the rules of individual judges and how judicial institutions (such as appellate review and the power to write separate opinions) affect the stability and enforceability of legal rules. These results are discussed in light of fundamental debates between legal and political perspectives on judicial behavior.