Indicators of the formation of precedent at the International Court of Justice

Abstract

This study expands upon prior analysis of the case citation network of the International Court of Justice (ICJ) by demonstrating that reverse page-rank outperforms hub and authority score in identifying significant sources of precedent. Application of reverse page-rank reveals that though ICJ decisions that are well grounded in prior cases tend to become more important sources of precedent, this relationship is weak when compared to the US Supreme Court. This tempers past conclusions that the ICJ has become more similar to common law systems but supports a view of the Court as an institution that balances consistency in its application of international law with the statutory limits on using its decisions as sources of such law. In addition, a novel method for constructing agreement networks between judges is leveraged to identify ICJ judges with influential positions. This provides evidence that certain judges may be more indicative of which decisions become important in the future. Though the strength of this influence is also limited, it nevertheless suggests that some ICJ judges may better represent the development of international legal precedent than others.