Protocolising Discretion : Administrative Law Justifications for Implementing Structural Fiscalistics in Financial Regulation

Administrative law has traditionally constrained the open texture of discretionary power through narrative reasons. In contemporary financial regulation, however, that model is increasingly strained by fragmented cross-border evidence, rule-dense regimes, and algorithmic mediation. This paper introduces Structural Fiscalistics (SF) not as a substantive decision engine, but as a pre-analytical governance interface for protocolising administrative discretion. SF decomposes the administrative act into a non-reversible three-layer pipeline—Evidence (Fiscal Epistemology), Structure (Fiscal Geometry), and Readout (Reason Codes)—through which discretionary choices become verifiable protocol branchings rather than post hoc narratives. The paper argues that this shift from rhetorical justification to structural execution is compatible with, and operationalises, common law requirements of legality, rationality, and procedural fairness. Applied to financial regulation, SF introduces replayability as a working standard for consistency, reduces narrative burden through a reason-code grammar, and furnishes courts with a pathway-audit interface for review. By mapping the 4-3-3-2 grammar onto classic grounds of judicial review, the paper provides a doctrinally legitimate blueprint for institutionalising SF. The framework relocates—rather than eliminates—discretion, shifting the locus of administrative justice from speculative reconstructions of subjective reasoning to the reviewable integrity of decision pathways.