Abstract: | Circuit splits, or conflicting rules across multiple U.S. Courts of Appeals, have important policy implications and dramatic effects on Supreme Court case selection, yet we know little about the incentives ideological lower courts face when deciding whether to initiate conflict. This article develops a formal model of a judicial hierarchy where lower court judges are subject to review by a high court with distaste for unresolved conflict, termed “split-intolerance,” and with uncertain preferences over policy. Lower courts may compete by investing costly effort in legal quality to make their rules more attractive. In equilibrium, lower courts may initiate conflict even when the odds of success before the high court are remote. Surprisingly, lower courts grow more likely to create conflict as the high court's split-intolerance increases; however, split-intolerance can also incentivize greater lower court effort. I present qualitative evidence illustrating the model's explanatory power. |