As a companion to the five regional reports in this volume, this chapter’s aim is a double one: first, to bring the comparison up to the regional level, and second, to analyse the international and domestic institutions, procedures, and mechanisms that affect how international human rights instruments influence domestic law. The chapter is therefore both a study in comparative international human rights law and a contribution to its methodology. Its structure is four-pronged. The first section clarifies the aim, object, and method of the comparison. The second section presents a comparative assessment of the Covenants’ domestic influence across regions and develops a grid of comparative analysis. The third section addresses the authority of the Committees’ interpretations of the Covenants, relying on a bottom-up comparative law argument. The fourth section discusses the role of human rights comparison and of regional human rights law in enhancing the legitimacy of the Committees’ future interpretations.