JFR-rg: A New Macroeconomic Framework for High-Debt, Low-Growth Economies under Financial Repression

Standard macroeconomic frameworks have correctly identified Japan's government debt - now exceeding 240% of GDP - as carrying substantial fiscal risk. Yet FRED data from 2013 to 2026 present an empirical record inviting a complementary perspective: debt ratios have stabilized, nominal GDP has exceeded 670 trillion yen (SAAR), and unemployment has remained near 2.6-2.7%. This paper formalizes these channels through the Japanese Financial Repression r-g (JFR-rg) model. Building on Blanchard (2019), the framework incorporates a financial repression bias (epsilon_t = pi_t - r^n_t, directly observable from FRED) and a non-linear exchange-rate channel. Three theoretical contributions extend the literature: (i) the Debt Sustainability Corridor, a characterization of stability in (epsilon_t, g^n*_t) space; (ii) the Normalization Ratchet, a path-dependence theorem showing that temporary policy errors generate persistently higher debt trajectories; and (iii) the Captive Financial System Parameter (phi_t), which endogenizes the institutional precondition for JFR-rg stability. Appendices H-L provide supporting empirical evidence (VAR, ARDL, Local Projections) showing the framework's claims are empirically disciplined and falsifiable. The core debt-dynamics propositions are anchored in the consolidated government budget identity (Layer L1), while selected propositions additionally rely on minimal structural assumptions; identification concerns apply only to the empirical Layer L2. Counterfactual simulations illustrate a Normalization Trap: aggressive rate hikes can produce counterproductive debt dynamics. For high-debt, low-growth economies sharing Japan's institutional characteristics, strategically deploying the resulting Repression Dividend into productivity-enhancing investment may represent a regime-contingent equilibrium possibility, conditional on the captive system condition being maintained.