The Dynamic of a Tax on Land Value: Concepts, Models and Impact Scenario (Spring-Ragain, 2025)

Summary

"The dynamic of a tax on land value: concepts, models and impact scenario" is a November 2025 arXiv preprint by Hugo Spring-Ragain, a doctoral student at the Centre d'études diplomatiques et stratégiques (CEDS) in Paris.[1] Re-checked 2026-08-10: it still has not appeared in any peer-reviewed venue. IDEAS/RePEc carries it only as an arXiv working paper — it was picked up by the NEP-URE "New Economic Papers" report for Urban and Real Estate Economics on 2025-12-15, which is an automated keyword-routed circulation digest, not a peer-review process — and lists no citing works.[2] No journal submission, referee report, or citation from an established urban-economics scholar was found. It is a single-author, self-declared unfunded working paper posted to arXiv's general-economics category. The paper builds a spatial-dynamic mathematical model of how a land value tax reshapes land value and construction activity across an urban area over time, extending the static comparative-statics tradition that dominates most LVT modeling (including the wiki's own Neidle/TPA model) into an explicitly time- and space-varying framework.

Spring-Ragain's institutional affiliation and other published work corroborate that he is a non-specialist author working outside mainstream urban/public economics. CEDS, per its own site and Wikipedia's summary, is "an accredited postgraduate school and think tank in diplomacy and international relations" whose doctoral program trains "serving diplomats," military officers, and senior civil servants — not an economics department.[3] Spring-Ragain's public author bio (The Conversation) self-describes him as "Économiste" specializing in "questions macro-économiques, l'économie publique ainsi que... l'économie de l'innovation et de l'industrie," with doctoral research on transposing quantum-mechanics concepts into macroeconomics.[4] His other 2025 arXiv preprint, "ℏE: an action constant for quantum economics," develops this quantum-economics framework directly — defining an economic analogue to Planck's constant and studying regime transitions via non-commuting operators on Hilbert spaces — confirming the unconventional-econophysics side of his output.[5] The paper on this page should be read as a rigorous but unvalidated theoretical exercise, not as evidence with the standing of peer-reviewed urban economics.

Model and Method

The paper models two coupled fields over a two-dimensional city, evolving through time: land value V(x,y,t) and built capital K(x,y,t). Land value decays at a rate driven by discounting, the land value tax rate τ, and a location-specific "centrality" growth term, diffuses spatially (modeling neighborhood spillovers via a Laplacian operator), and is replenished by the productive output of built capital. Built capital accumulates through investment that activates only once local profitability crosses a threshold, net of depreciation. The system is solved analytically for its steady states and numerically via finite-difference and stochastic (Euler–Maruyama) simulation. An appendix separately re-derives the standard partial-equilibrium result that a land value tax, unlike a per-unit or ad valorem commodity tax, creates no wedge between the price paid and price received because land supply is fixed — the tax is instead fully capitalized into a lower land price, consistent with the Georgist tax-neutrality case already carried by this wiki via ATCOR and deadweight loss theory.

The model's parameters (productivity, discount rate, tax sensitivity, diffusion coefficient, and so on) are illustrative constants chosen for tractability, not calibrated to any real city's data. No empirical land-price, construction, or tax-revenue dataset is used anywhere in the paper.

Key Findings

• A transcritical bifurcation in the tax rate. The model's central analytical result is that an interior equilibrium of positive land value and capital investment exists only when the combined discounting-plus-tax "decay rate" exceeds a profitability threshold (α > θ). At the critical tax rate τ_c(x,y), the system switches between an "inactive" regime (no net investment, land value and capital decay to zero) and an "active" regime where LVT revenue and construction coexist in equilibrium. Central, high-productivity locations tolerate a higher τ_c before losing the active regime than peripheral ones — a formal statement of the intuitive claim that a uniform LVT bites hardest at the urban edge first.
• Diffusion smooths, not destabilizes. Spatial diffusion in land value dampens (rather than amplifies) high-frequency spatial variation — the model finds no Turing-style pattern instability, because only the land-value field diffuses.
• Ambiguous distributional/spatial effect. Numerical Lorenz-curve and Gini-index simulations of "attractiveness" (Ψ = productivity ÷ effective decay rate) find inequality falls modestly as τ rises within a moderate range (illustrative Gini values move from 0.394 to 0.377 in the paper's baseline simulation), which the author interprets as a temporary equalizing effect before "re-stratification" toward the center at higher tax rates. This is a simulated property of the author's own parameterization, not an empirical finding about any real housing market.
• Robustness checks. The qualitative bifurcation structure is shown to survive under three alternative productivity-decay profiles (exponential, polycentric, suburban-flat), under spatial discretization into concentric rings, and under a spatially-graded tax rate — evidence the mathematical result is not an artifact of one specific functional-form choice, though this says nothing about whether the model's assumptions describe real cities.
• Stochastic extension. A version with mean-reverting random shocks to productivity and centrality shows the deterministic steady state becomes a "stochastic attractor" that land value and capital orbit rather than settle on — offered as a closer analogy to observed boom-bust cycles in real urban land markets, though again without empirical calibration.

Limits and Honest Assessment

This is a theoretical contribution only: an internally consistent mathematical restatement and extension of the Georgist claim that LVT does not distort land use, cast in the language of reaction-diffusion dynamical systems. Its value to the wiki is illustrative — it shows that the standard static-neutrality result (Appendix A) survives the addition of space, time, diffusion, and stochastic shocks in at least one stylized model — but it carries none of the empirical weight of, for instance, the Pennsylvania split-rate literature or Denmark/Estonia implementation data already on this wiki. No claim in this paper should be cited as evidence about a real jurisdiction's likely LVT outcomes — as confirmed above (2026-08-10 re-check), it remains an unreviewed preprint with no independent check by other economists on record.

Bears On

• Concept: Land Value Tax — a formal dynamical-systems restatement of the tax-neutrality argument
• Concept: ATCOR and Deadweight Loss — Appendix A's incidence derivation matches these directly
• Research: What Would a Land Value Tax Actually Do? (Neidle/TPA) — a contrasting empirical/static microsimulation of a real jurisdiction's LVT, versus this paper's theoretical/dynamic approach

See Also

• Land Value Tax
• What Would a Land Value Tax Actually Do? (Neidle / Tax Policy Associates, 2026)
• ATCOR
• Deadweight Loss
• Henry George Theorem

Sources

1. Hugo Spring-Ragain (2025), "The dynamic of a tax on land value: concepts, models and impact scenario," arXiv:2511.21766 [econ.GN], submitted 25 November 2025 — used for the full model, all findings, and the author-affiliation statement (CEDS, Paris) on the paper's title page; full text read and checked against the page's specific figures (e.g. the Gini 0.394→0.377 range), which match the PDF exactly. arxiv.org/abs/2511.21766 · full-text PDF.
2. IDEAS/RePEc record for arXiv:2511.21766 — used to confirm the paper's only circulation is as an arXiv working paper and its NEP-URE dissemination (2025-12-15), with no journal listing and no recorded citing works. ideas.repec.org/p/arx/papers/2511.21766.html.
3. Centre d'Études Diplomatiques et Stratégiques (CEDS) — official site and Wikipedia summary — used to confirm CEDS is a diplomacy/international-relations postgraduate school and think tank, not an economics department. ceds.fr/en · Wikipedia.
4. Hugo Spring-Ragain, author profile, The Conversation — used for the author's own bio statement (self-described economist, macro/public/innovation economics, doctoral work on quantum-economics modeling). theconversation.com/profiles/hugo-spring-ragain-2264853.
5. Hugo Spring-Ragain (2025), "ℏE: an action constant for quantum economics," arXiv:2509.02647 [econ.GN] — used to confirm the content of the author's other 2025 preprint (an econophysics framework applying quantum-mechanical operators to macroeconomic variables), corroborating the author-background assessment above. arxiv.org/abs/2509.02647.