This book offers a novel, multi-pronged empirical analysis of legal reasoning in commercial disputes, comparing data across three different axes: the judicial–arbitral divide, the domestic–international divide, and the common law–civil law divide. In so doing, this text provides important insights into how judges and arbitrators resolve complex commercial disputes in both national and international settings and conducts important comparisons between different procedures. The study includes three different empirical methodologies: a large-scale international survey, a series of semi-structured interviews, and a detailed quantitative (coding) exercise. Results from the three research strands are cross-verified through various triangulation techniques and tested against conventional wisdom regarding legal reasoning. This work will help judges, arbitrators, practitioners, clients, and scholars understand how legal reasoning is conducted in different settings, thereby improving the practical and understanding of how commercial disputes are resolved.