Fiscal deterioration alone does not cost the United States its safe asset status: safety is relative, and with no credible alternative, investors stay (the There-Is-No-Alternative, or TINA, effect). Status is lost when institutional erosion degrades market depth and raises coordination uncertainty; the Cournot–Nurkse–σ cascade then brings the run forward, to 2043 under Institutional Erosion, with debt reaching 380 percent of GDP by 2055.
Why status holds. Safety is relative: with no credible alternative, fiscal deterioration alone does not move investors, and invoicing complementarities and the convenience yield buffer the debt path for decades.
How status is lost. Institutional erosion degrades the Market factor; market shares shift toward challengers, the Nurkse index rises, coordination noise grows, and a self-fulfilling run becomes available—the Cournot–Nurkse–σ cascade.
filled: the section is about the TINA effect filled: the section is about the erosion cascade open: the theme is not the section's subject
Safe asset status is an equilibrium property, not an intrinsic one: it rests on investors' coordination and on the absence of a credible alternative. The joint realization of fiscal deterioration and institutional erosion produces a run at 2043, with debt reaching 380 percent of GDP by 2055; either force alone does not.
What does the literature establish about how safety is won and lost?
The three literatures agree that safety is won and lost in equilibrium: information insensitivity and the coordination game set the demand side, the strategic supply game sets provision, and the fiscal arithmetic bounds the issuer. The 2022 sanctions episode anchors the Market-factor channel empirically.
How do the three literatures combine into one dynamical system?
Two games joined by five feedback channels: investor coordination over a two-factor fundamental, Fiscal and Market, and Cournot competition in supply. Strategic restriction raises the safety premium and amplifies the Triffin temptation; rising multipolarity raises the Nurkse index and coordination noise. Three propositions carry the results: the TINA Corollary, the Cournot–Nurkse–σ Cascade, and Debt Overhang Absorption.
Figure 1 (Cournot equilibrium shares at t = 0); Equation 6 (the Nurkse instability index).
What parameter values make the calibrated system the world of 2025?
The calibrated starting state is hegemonic: the United States holds approximately 92 percent of safe-asset supply, the Nurkse index approximately 12, and the convenience yield approximately 54 basis points against the 73 basis point ceiling of the literature.
Table 1 (Key parameter calibration); Table 2 (Sovereign calibration at t = 0).
What futures does the calibrated system produce?
Four of the five scenarios end 2055 with status intact, debt notwithstanding; only Institutional Erosion produces a run, at 2043. Fiscal deterioration alone leaves status intact under the TINA effect; the European Union challenge raises instability without a run; China's opening does not bind.
Table 3 (Scenario definitions); Table 4 (Summary results at 2055); Figures 2 through 6 (debt, hazard, Nurkse–σ, shares, convenience yield).
How sensitive is the run year to the feedback parameters?
The run year moves by about eight years across the (σ₁, λ) grid, from about 2040 to about 2048: the feedback parameters set the timing, institutional erosion sets the outcome. The Monte Carlo brackets the run year at 2036 through 2049 between the tenth and the ninetieth percentile.
Figure 7 (run year over the (σ₁, λ) grid); Figure 8 (Monte Carlo run-year distribution).
What does the model capture, and what does it miss?
The emergent Cournot–Nurkse–σ cascade is the model's contribution: no single literature generates it. The model omits cyclical dynamics and private safe assets, among the limits the section states; the run year is uncertain by a decade or more, and the qualitative pattern is the robust conclusion.
What is the robust conclusion?
Status is more resilient than the fiscal trajectory suggests and less resilient than the TINA effect suggests. The hegemon's trap is strategic: the monopoly premium amplifies the temptation to borrow, and an emerging challenger endogenously generates the instability through which status is lost.