Sectional Reading under the Fiscal Geometry Framework: Computing SITI and Interpreting SIDI on the X–Y Plane

This white paper introduces a sectional reading protocol within the two-axis Fiscal Geometry (FG) framework for examining institutional events and policy regimes. Rather than introducing new axes or redefining the underlying geometry, the approach operates strictly on the existing X–Y plane and applies a thematic slice to a defined institutional domain, such as the Common Reporting Standard (CRS) or OECD Pillar Two.

Within each section, the same dataset produces two complementary outputs: (1) an arithmetic intensity measure, the Sectional Institutional Tension Index (SITI), and (2) a geometric interpretation layer, Sectional Institutional Distortion (SIDI), used to read divergences between numerical aggregation and spatial manifestation. The paper formalizes a three-region geometric structure that separates computation from interpretation, preserving arithmetic rigor while retaining structural observability for audit, policy, and institutional analysis.