The Price of Failure Why Post-Validation Regimes Cannot Secure Irreversible Systems

Abstract/Description This paper establishes a structural and information-theoretic proof that retrospective governance—where actions execute first and admissibility is evaluated afterward—carries an unavoidable and non-vanishing "monitoring tax". Key Findings: Information Destruction: Once an irreversible action executes, the admissibility state that existed at that moment is partially destroyed. Reconstructing it requires continuous information acquisition proportional to system activity. The Regulatory Ratchet: Failures in retrospective systems generate regulatory expansion (monitoring and reporting) rather than structural prevention. This leads to an endogenous accumulation of compliance costs that rarely revert. Economic Dominance: Over sufficiently long horizons, retrospective governance is economically dominated by Execution-Time Admissibility architectures. This dominance holds even if compliance intensity remains constant, due to residual failure probability and socialized losses. Institutional Shift: The paper proposes a "Regulatory Safe Harbor" for operators who adopt pre-validation, aligning private incentives with structural safety and shifting insurance from "pooling risk" to "pooling certainty". Applications:The results are domain-independent, applying to financial settlement, autonomous systems, surgical robotics, medical decision-making, and regulatory frameworks like the EU AI Act.