Toward a General Law of Epistemic Degradation: Coherence Dynamics Across Macroeconomic Forecasting, Clinical Guideline Drift, and Scientific Reproducibility

Paper III of this series established the GYORᴹ coherence framework across six domains. Paper IV tests whether cross-domain structural invariance constitutes a general law. The corpus is expanded to ten domains including macroeconomic forecast revision (GDP vintage analysis), clinical guideline drift (HRT reversal, blood pressure threshold), scientific reproducibility (OSC replication corpus), and Antarctic sea ice ensemble divergence under SSP5-8.5 (T₃, no ground truth). All ten domains pass the operator sequence falsification test (λᴹ→γᴹ→κᴹ→ρᴹ). Formal operator equations, MDI_scaled computation rules, and six explicit falsification conditions (F1–F6) are provided. The General Law of Epistemic Degradation (GLED, L1–L6) is stated as a formally falsifiable proposition with explicit boundary conditions. A Limitations section acknowledges three open vulnerabilities and specifies the path to formal mathematical derivation in Paper V. GCM Observatory Series, Paper IV. License: CC BY 4.0.