Why do some international courts and judges extensively cite decisions from other courts whereas others do not? I argue that judges anticipate what external citations communicate to third parties. Depending on their institutional environments, judges expect more or less scrutiny for engaging sources of law other than the primary treaties that they are delegated to interpret. A global analysis of cross-citation patterns and an in-depth analysis of citations to and from the European Court of Human Rights (ECtHR) are consistent with the implications of this argument. Contrary to its transnationalist reputation, the ECtHR is cautious in citing other courts although ECtHR judges regularly refer to external decisions in separate opinions. The propensity of ECtHR judges to cite external sources is correlated with judicial ideology. The findings have implications for debates on transjudicial communication, the diffusion of international legal norms, the fragmentation of international law, and international judicial behavior.
The paper is written from a social sciences perspective and includes a 'Global Matrix of International Court Citation Patterns'. Enjoy reading!