Rendering Tax Residence as an Institutional Entry Node A Demonstration of Fiscal Geometry

This paper presents a methodological demonstration of Fiscal Geometry (FG) as a representational framework for rendering legal classifications observable. Using tax residence as a focal case, the paper reframes residence determination not as a technical rule or compliance outcome, but as an institutional entry node through which individuals and households are routed into specific fiscal systems. The study introduces a node-based representation that decomposes tax residence into observable inputs, rule logics, decision states, and downstream routing consequences. Rather than advancing doctrinal interpretation or policy evaluation, the paper focuses on how residence functions structurally as a gateway that organizes filing obligations, reporting exposure, and long-term fiscal positioning. The framework is demonstrated through a comparative illustration across four jurisdictions—the United Kingdom, Canada, the United States, and Japan—selected to reflect differences in legal tradition, evidentiary preference, and sovereign design. The comparison shows how identical mobility facts can generate divergent institutional pathways, not due to interpretive disagreement, but due to differences in classification architecture. The contribution of the paper is methodological. It establishes a visibility-first approach to legal classification, providing a neutral representational interface that supports structural observation, comparative analysis, and future computational or empirical extensions without prescribing implementation or compliance guidance.