Lower Court Influence on High Courts: Evidence from the Supreme Court of the United Kingdom

Do lower court judges influence the content of Supreme Court opinions in the United Kingdom? Leveraging original data, we analyze opinion language adoption practices of the UK Supreme Court. We advance a theory where the justices’ choices to adopt language from lower court opinions are influenced by Supreme Court-level attributes and Court of Appeal case characteristics. We uncover compelling evidence that UK Supreme Court justices incorporate language extensively from the written opinions of the Court of Appeal of England and Wales. Our findings have significant implications for opinion formulation, doctrinal development, and higher and lower court interactions within comparative courts.