The Sovereign Yield Mirage — Central Bank Digital Currencies (CBDCs), Programmable Scarcity, and the Death of Liquid Counterparty Autonomy

The historic stability of decentralized trade rested on the structural separation between asset ownership and state liability through unconditioned peer-to-peer bearer liquidity. This monograph analyzes the systemic transition from physical cash to programmable Central Bank Digital Currency (CBDC) architectures. By formalizing protocol-enforced demurrage equations, time-decay functions, and real-time ledger permissions, we demonstrate how state monetary authorities convert private capital from a sovereign store of value into an expiring, conditional lease on state-sanctioned liquidity. Furthermore, we construct a mathematical failure model governing capital mobility collapse under programmable spending constraints and establish the universal structural invariants required to defend counterparty autonomy against centralized ledger enclosure.