These fiscal developments do not exist in isolation. They interact with a geopolitical realignment in which BRICS economies are actively constructing non-dollar settlement architectures, a domestic political environment characterized by persistent structural deficits on both the spending and revenue sides, and a monetary policy framework constrained by inflation running persistently above the Federal Reserve's 2% target. The analytical challenge is that these forces are interpreted through fundamentally different theoretical lenses—each of which prescribes distinct predictions for bond rates, the dollar, and real economic activity.
The CBO's long-run baseline, as of the December 2025 update, projects the following trajectory for debt held by the public:
The OBBBA, estimated to add several trillion dollars in net new debt through permanent extension of tax provisions and expanded infrastructure spending, is expected to shift this trajectory upward, with IBISWorld projecting the 2026 debt-to-GDP ratio at approximately 127.7%.
Three structural factors underpin the widening deficit:
1. Aging demographics and mandatory spending: Federal healthcare spending (Medicare and Medicaid) is projected to rise from 6.0% of GDP in 2026 to 8.1% of GDP by 2056. Social Security outlays follow a similar trajectory driven by the retirement of the Baby Boom cohort.
2. Revenue shortfall: Federal revenues are projected to rise only from 17.5% to 18.8% of GDP over 2026–2056, against total spending rising from 23.3% to 27.9% of GDP. The persistent structural gap is approximately 5–9 percentage points of GDP.
3. Compounding interest dynamics: Net interest payments are projected to grow at 7.5% annually from FY2026 to FY2036, reaching \$1.8 trillion (4.1% of GDP) by FY2035. Over the 2024–2035 window, the interest burden as a share of federal revenue is projected to double, from ~9% to ~30%. This internal compounding—whereby higher debt raises interest costs, which raises borrowing, which raises debt—is the definitional form of a debt spiral.
The interest-rate–growth differential, often denoted \( r - g \), is the key sustainability parameter. When \( r > g \), the debt-to-GDP ratio grows without bound absent primary surpluses. With 10-year yields at approximately 4.4% and trend nominal GDP growth near 4.0–4.5%, the U.S. currently operates near or modestly above the \( r = g \) threshold, making the primary deficit the decisive variable.
The 10-year Treasury yield can be decomposed as:
As of mid-2025, the 10-year yield ranged between 4.38% and 4.55%, with the bear steepening trend extending the 30-year above 5% following the Moody's downgrade. The "bear steepening" pattern—long rates rising while short rates are anchored or declining—is analytically distinct from the "bear flattening" of 2022–2023, which was driven by Fed rate hikes. Bear steepening reflects the market's reassessment of term and fiscal risk, consistent with the fiscal dominance or bond vigilante narratives.
The May 16, 2025 Moody's downgrade from Aaa to Aa1 completed the trifecta of sovereign downgrades (following S\&P in 2011 and Fitch in 2023). Moody's cited: a decade-long deterioration in fiscal metrics relative to highly rated peers; a projected federal deficit approaching 9% of GDP; and interest costs absorbing 18% of revenue in 2024, rising to a projected 30% by 2035. The downgrade occurred simultaneously with Congressional debate over the OBBBA reconciliation package.
The bond market reaction diverged significantly from the 2011 episode. In 2011, the S\&P downgrade was accompanied by a fall in 10-year yields as capital fled to Treasuries in a classic flight-to-safety response. In contrast, the 2025 Moody's downgrade and subsequent fiscal expansion debate was accompanied by rising long yields—with the 30-year briefly exceeding 5%—and a contemporaneous weakening of the dollar index. This "sell America" dynamic represents a structural shift: Treasuries are no longer unambiguously the safe haven in risk-off episodes, at least in the long-duration segment.
Bond vigilantism—the mechanism by which market participants discipline fiscal profligacy through yield increases—operates through several channels: 1. Premium for rollover risk: With approximately \$50 billion per week in Treasury issuance, any reduction in demand elasticity among foreign official holders requires domestic private absorption at higher clearing yields. 2. Inflation risk premium: Core PCE inflation hovering at approximately 2.8% as of early 2026, combined with OBBBA fiscal stimulus, has widened the inflation risk premium embedded in long-duration yields. 3. Liquidity and convexity: Reduced foreign official holdings reduce the natural buyer base for off-the-run Treasuries, widening bid-ask spreads and liquidity premia.
The CBO estimates that for every new dollar of government borrowing, private investment falls by approximately \$0.33, consistent with standard loanable-funds crowding out. This 33-cent-per-dollar elasticity implies that the projected debt trajectory will reduce private investment by 13.6% by 2035, 17.1% by 2055, and 21.6% by 2075, according to the EY/QUEST macroeconomic simulation. The GDP impacts are commensurately large: a reduction of \$340 billion relative to a stabilized-debt baseline by 2035, growing to \$1.1 trillion by 2055 and \$1.8 trillion by 2075.
Higher borrowing costs transmit to the private economy through:
The dollar's "exorbitant privilege"—Valéry Giscard d'Estaing's characterization of the asymmetric advantage the U.S. derives from dollar reserve status—manifests as: the ability to borrow at lower rates than the U.S. fiscal position would otherwise command; persistent U.S. current account deficit financing without triggering a balance-of-payments crisis; and seigniorage income from dollar-denominated claims held globally.
This privilege operates through several structural mechanisms: 1. Safe-haven demand: In risk-off episodes, global investors purchase dollar assets, appreciating the dollar and reducing U.S. financing costs precisely when U.S. fiscal needs may be elevated. 2. Petrodollar recycling: Oil transactions denominated in dollars generate persistent structural demand for dollar-denominated assets from oil-exporting nations. 3. Network externalities: Dollar denomination reduces transaction costs in global trade, creating a coordination equilibrium that is self-reinforcing absent a credible alternative with equivalent liquidity and legal certainty.
The dollar's share of global foreign exchange reserves declined from approximately 72% in 2001 to 59% by 2025, and to 56.32% in Q2 2025 according to the IMF COFER database. Two distinct interpretations of this trend require separation:
Cyclical de-risking: What has been observed is dollar hedging rather than structural de-dollarization. Periods of U.S. policy uncertainty—trade policy volatility, threats to Fed independence, executive-branch criticism of the FOMC—generate temporary portfolio diversification that reverses as policy stabilizes. The dollar dropped more than 10% in 2025 but retained structural dominance in trade invoicing and financial contracts.
Structural de-dollarization: A competing view, supported by reserve composition data, gold accumulation patterns, and BRICS institutional development, holds that the erosion is secular and is being reinforced by structural forces:
The CBO's long-run projections suggest the dollar's share of global currency reserves could fall to 45–50% by 2055, reflecting the secular trend absent a reversal in U.S. fiscal credibility or significant global governance changes.
A critical variable in 2025–2026 was the perceived erosion of Fed independence. The appointment of executive-branch-aligned members to the Fed's Board of Governors, public presidential criticism of the Fed Chair, and a criminal investigation against the Fed Chair announced in January 2026 introduced a novel "political discount" into dollar credibility assessments. Global investors price central bank independence as a pillar of currency credibility; erosion of this independence signals that the inflation target may become subordinate to fiscal or political objectives—precisely the fiscal dominance scenario.
The dollar's year-to-date decline of more than 10% in 2025 occurred against a backdrop of normally dollar-positive conditions (high relative U.S. interest rates, geopolitical risk), suggesting that the political credibility channel was operative and material.
The near-term GDP growth baseline for 2026 is approximately 2.2%, supported by residual fiscal stimulus from the OBBBA. This "sugar high" dynamic—elevated near-term growth funded by deficit expansion—is predicted to fade as: (a) the one-time multiplier effect of tax cuts and infrastructure spending dissipates; (b) higher long-term yields reduce investment; and (c) trade policy uncertainty (tariff escalation cycle) suppresses business capital formation.
The EY/QUEST modeling projects that relative to a stabilized-debt counterfactual, the current debt trajectory will reduce the size of the economy by \$340 billion in 2035—a meaningful drag that compounds over time. Employment is projected to be approximately 1.2 million jobs lower by 2035 relative to the stabilized-debt baseline, rising to 2.7 million by 2055 and 3.6 million by 2075.
The fiscal arithmetic is stark: net interest payments constituted approximately 15% of all federal spending in the first nine weeks of FY2026. As interest costs approach 30% of federal revenue by 2035, the capacity to maintain public investment in infrastructure, R\&D, defense, and human capital is mechanically compressed without tax increases or compensating spending cuts. This dynamic—sometimes called fiscal arthritis—implies that debt service has first claim on future revenue growth, leaving discretionary investment as the residual.
The structural spending drivers reinforce this compression: federal healthcare spending rising from 6.0% to 8.1% of GDP by 2056, Social Security growth reflecting demographic inevitabilities, and interest compounding all claim revenues before discretionary appropriations.
The EY/QUEST model translates the crowding-out of private investment into labor market outcomes through the production function channel. Reduced capital formation lowers the capital-labor ratio, compressing labor productivity growth and, consequently, real wage growth. Under the current debt trajectory:
The Federal Reserve faces a near-term policy trilemma with no clean resolution:
1. Contractionary monetary policy (maintaining high rates to combat inflation): This path stabilizes inflation but raises Treasury debt service costs, accelerates fiscal deterioration, and risks tipping the economy into recession.
2. Accommodative monetary policy (cutting rates to support growth): This path reduces debt service costs but risks unanchoring inflation expectations in a fiscal dominance environment, potentially triggering the bond vigilante mechanism and steepening the yield curve from the long end.
3. Financial repression (holding nominal rates below inflation): This path reduces the real value of outstanding debt (a partial inflation tax) but erodes dollar credibility, accelerates de-dollarization, and penalizes savers.
Core PCE at approximately 2.8% in early 2026, above the 2% target, constrains aggressive rate cutting. Market pricing as of mid-2025 implied two 25-basis-point cuts by year-end 2025, consistent with gradual accommodation rather than a pivot. The "higher-for-longer" regime, in which short-term rates remain elevated while long-term rates continue to rise on fiscal concerns, is the bear-steepening scenario most consistent with fiscal dominance dynamics.
Japan's fiscal trajectory offers the most direct high-debt precedent, though with critical structural differences. Japan's debt-to-GDP ratio exceeded 100% in the late 1990s and currently exceeds 250%; yet Japan has maintained: near-zero interest rates through Bank of Japan yield curve control (YCC), negligible inflation until 2022–2023, and no sovereign default or acute currency crisis. The mechanism is: high domestic savings rate (providing a captive buyer for JGBs), persistent current account surplus (financing external net creditor status), and central bank willingness to expand its balance sheet without limit.
The U.S. diverges structurally from Japan on all three stabilizing factors: the U.S. household savings rate is substantially lower, the U.S. runs a persistent current account deficit, and the Fed's capacity to suppress long yields through QE is constrained by its inflation mandate. The U.S. analog to YCC would require explicit yield caps, which would likely accelerate dollar depreciation and de-dollarization.
A critical analytical distinction in the literature concerns solvency versus liquidity. The U.S. is unambiguously solvent in nominal terms—dollar-denominated debt can always be serviced through money creation. The relevant risk is real solvency: whether the U.S. can maintain sufficient real GDP growth and primary surplus capacity to stabilize the real value of outstanding debt. The \( r - g \) condition:
The available evidence supports the following conclusions:
On bond rates: The bear steepening of the yield curve, the post-Moody's long-end spike, and the persistent elevation of the term premium are most consistent with the fiscal dominance and bond vigilante narratives. The evidence is inconsistent with a pure MMT prediction that yields are simply a policy variable unaffected by debt supply, and inconsistent with the secular stagnation prediction that yields should be compressing. The 2025 episode is empirically distinguishable from 2011: flight-to-safety buying no longer automatically depresses long-end Treasury yields during risk-off episodes.
On the dollar: The evidence supports a structural but gradual erosion of dollar reserve share—more consistent with the structural de-dollarization narrative than with the cyclical hedging view. The petrodollar structural threat from EV adoption and the institutional architecture being constructed by BRICS nations represent genuine long-run challenges to dollar hegemony. However, the absence of a credible alternative reserve currency with equivalent liquidity, legal certainty, and depth means that de-dollarization is a decades-long transition, not an imminent cliff.
On near-term growth: The 2.2% 2026 GDP baseline is primarily a fiscal-stimulus effect from the OBBBA. The structural headwinds—crowding-out, interest cost compression of discretionary investment, and higher private borrowing costs—are building with a 2–5 year lag. The near-term risk is a growth deceleration in 2027–2028 as fiscal multiplier effects fade and monetary tightening continues to transmit through the economy.