This book investigates the extent and nature of foreign legal precedent cited by constitutional courts worldwide. The International Association of Constitutional Law established a dedicated Interest Group to conduct a comprehensive survey on this topic, aiming to empirically analyze both quantitative and qualitative indicators of transjudicial communication. The research seeks to assess the reliability of existing studies on this phenomenon and explore the potential for progressive constitutional convergence between common law and civil law traditions. By including studies from scholars across diverse global regions and legal systems, the work provides significant evidence regarding transnational constitutional communication between courts.

This work presents the findings of a significant international survey on the use of foreign precedents by constitutional judges, offering empirical data on transjudicial communication. The inclusion of studies from a wide array of global jurisdictions and legal traditions provides a comprehensive overview of current practices. The research aims to shed light on the extent of constitutional convergence across different legal systems. The findings are published here for the first time, offering the best evidence to date on this subject.