TECHNOLOGY, REGULATION, AND THE DIVERGENT TRAJECTORIES OF RETAIL AND CROSS-BORDER CENTRAL BANK DIGITAL CURRENCY

Background. Central bank digital currency (CBDC) sits where fast-moving cryptographic and ledger technology meets fast-moving regulation, yet the two are usually studied separately, and retail and cross-border uses are usually treated as one object. Between 2024 and 2026 major jurisdictions made sharply different regulatory choices. Research Purpose. This review examines how advanced cryptographic solutions and hybrid blockchain architectures interact with evolving regulatory frameworks to shape economic outcomes and user adoption, and how that interaction differs between retail and cross-border implementations. Research Method. We conduct a critical review. A Scopus search on 8 October 2026 (1,418 records, 1,045 retained) maps the field, and a purposive selection of peer-reviewed studies and official publications is synthesised around four research questions. Findings. Technology and regulation terms co-occur at about the level expected by chance, and evidence on cryptographic feasibility and on adoption comes largely from separate literatures. Hybrid, two-tier architectures dominate, and the tension between privacy and anti-money laundering is increasingly handled through cryptographic design. Retail adoption is weak in every live system reviewed, while wholesale cross-border arrangements show the clearest technological value but are limited by governance. Regulatory choices since 2024 now shape outcomes more than technical feasibility does. Conclusion. Technology and regulation co-evolve, and retail and cross-border CBDC face different binding constraints. We offer a co-evolution framework with four falsifiable propositions and argue that CBDC should be studied together with regulated stablecoins and tokenised deposits. Keywords: central bank digital currency, privacy-enhancing technologies, distributed ledger technology, cross-border payments, financial regulation.