The federal circuit courts are, for all intents and purposes, the final arbiters of federal litigation in the United States. They render thousands of decisions yearly, making the likelihood of Supreme Court review for any individual case minimal. The sheer number of cases they decide, combined with the improbability of being reviewed by the Supreme Court, make circuit courts the engines of legal policy making in the United States. Yet, scholars lack sophisticated data on the United States Courts of Appeals and the policy preferences of the judges who serve on them, leaving them unable to examine empirically how law evolves on the United States Courts of Appeals, whether circuit court judges render decisions based on the law or their policy goals, what leads judges to bargain with one another and accommodate their colleagues' requests, and whether circuit judges fear retribution from Congress and the president.
To estimate circuit court judges' preferences, the investigators employ the most current and sophisticated measurement techniques, and do so in a way that facilitates comparisons across the twelve U.S. circuits, the Supreme Court, Congress, and the president. These scores enable researchers to determine how liberal or conservative a particular circuit court judge is, and to compare that judge's underlying ideological propensity with other judges in their circuit, judges in alternative circuits, and with members of Congress and the president.
