Fiscal trajectory and sovereign interest burden
Updated
Summary
This indicator tracks how much it costs governments to carry their debt, and where that cost is heading. The core measures are interest paid as a share of GDP, of revenue or of total spending, alongside the debt ratio and the deficit. Interest cost depends on three things: how much debt there is, the average rate paid on it, and how fast old debt is refinanced at new market rates. Because most debt is fixed-rate and long-dated, the average rate on the stock moves slowly toward market yields; bills, floating-rate notes and inflation-linked bonds pass changes through faster. The node covers the US (Treasury, CBO), the euro area (Eurostat, ECB), the UK (ONS, OBR), France (INSEE, Agence France Trésor), Italy and Japan (Ministry of Finance). The key long-run test is r versus g: if the effective interest rate exceeds nominal growth, the debt ratio rises unless the government runs a large enough primary surplus.
Key numbers
US net interest on the public debt, FY2026 first 11 months: $1,052 billion (+12% y/y); DoD military $833 billion (as of 2026-09-09). Source: cbo.gov
US FY2026 deficit (CBO estimate): $2.0 trillion (+$218 billion vs FY2025) (as of 2026-10-08). Source: cbo.gov
US average interest rate on marketable debt vs 10-year yield: about 3.5% (Fiscal Data via JEC) vs 4.96% 10-year par yield on 2026-10-22 (as of 2026-10-22). Source: home.treasury.gov
CBO baseline net interest, 2026 and 2036: $1,039 billion (3.2% of GDP) to $2,144 billion (4.6%) (forecast) (as of 2026-02-11). Source: cbo.gov
Euro area government debt / deficit, 2025: 87.7% / 3.0% of GDP (as of 2026-10-21). Source: ec.europa.eu
Euro area government debt, end-Q2 2026: 88.8% of GDP (provisional) (as of 2026-10-21). Source: ec.europa.eu
ECB deposit facility rate: 2.50% (from 2026-09-16) (as of 2026-09-10). Source: ecb.europa.eu
UK central government debt interest, Sept 2026 / FYTD: £10.9 billion (£4.0 billion index-linked uplift) / £60.8 billion (as of 2026-10-21). Source: ons.gov.uk
UK debt interest 2025-26: £110 billion, third-largest spending area (as of 2026-07-07). Source: obr.uk
France public interest charges 2026 to 2027: €79.2 billion to €91.2 billion (government projection) (as of 2026-10-01). Source: info.gouv.fr
Italy interest expenditure 2025: €87.2 billion (as of 2026-10-06). Source: documenti.camera.it
Japan interest cost, FY2026 budget to FY2027 request: ¥13.0 trillion at 3.0% to ¥16.6 trillion at 3.8% assumed rate (as of 2026-09-30). Source: mof.go.jp
Timeline
2026-10-22 — US 10-year par yield 4.96%, down from 5.13% a day earlier and 5.24% on 2026-10-01. (Source: home.treasury.gov)
2026-10-21 — Eurostat: euro area 2025 deficit 3.0% and debt 87.7% of GDP; end-Q2 2026 debt 88.8%. (Source: ec.europa.eu)
2026-10-21 — ONS: UK September debt interest £10.9 billion, £4.0 billion from index-linked uplift; net debt £3,005.0 billion (94.0% of GDP). (Source: ons.gov.uk)
2026-10-17 — Lagarde at the IMFC: long-term rates up notably; high-debt countries should consolidate. (Source: ecb.europa.eu)
2026-10-14 — JEC brief: average rate on US marketable debt about 3.5%, about one-third of debt matures within a year. (Source: jec.senate.gov)
2026-10-08 — CBO: FY2026 deficit $2.0 trillion; separate report shows +150 bp rates add $6.0 trillion to 2026-2036 deficits. (Source: cbo.gov)
2026-10-06 — Italian Chamber dossier: 2025 interest spending €87.2 billion; long-rate assumptions raised about 30 bp. (Source: documenti.camera.it)
2026-10-01 — French 2027 budget bills: interest charges €79.2 billion (2026) to €91.2 billion (2027); 2026 deficit revised to 5.4%. (Source: info.gouv.fr)
2026-09-30 — MOF Fiscal System Council: FY2027 interest request ¥16.6 trillion at an assumed 3.8%, a record. (Source: mof.go.jp)
2026-09-10 — ECB raises key rates 25 bp; deposit rate 2.50% from 2026-09-16. (Source: ecb.europa.eu)
2026-09-09 — CBO: US net interest $1,052 billion in FY2026's first 11 months, up 12%. (Source: cbo.gov)
2026-09-04 — Japan's finance minister: long-term JGB yield about 3%, highest in roughly 30 years. (Source: mof.go.jp)
2026-08-28 — MOF FY2027 request: debt service ¥36.64 trillion, interest ¥16.59 trillion. (Source: mof.go.jp)
2026-08-20 — JEC: US total public debt at a record $40.047 trillion. (Source: jec.senate.gov)
2026-07-07 — OBR: UK debt interest £110 billion in 2025-26, third-largest spending area. (Source: obr.uk)
2026-05-29 — INSEE: French interest charges €64.7 billion in 2025, up 11.2%. (Source: insee.fr)
2026-02-11 — CBO baseline: net interest $1,039 billion in 2026, above defense; debt to 120% of GDP by 2036. (Source: cbo.gov)
Key actors and links
U.S. Treasury (actor:us-treasury): Issues and refinances US debt; its auction mix (22.2% bills) sets how fast higher yields reach the interest bill.
United States (country:united-states): Largest dollar interest bill: CBO puts FY2026 net interest above $1 trillion and above defense.
Federal debt/interest burden (indicator:federal-debt-interest-burden): US-specific sibling node; this node is the cross-country version of the same burden.
U.S. fiscal deficits (theme:us-fiscal-deficits): The $2.0 trillion FY2026 deficit adds to the debt stock that interest is paid on.
Sovereign debt burden (theme:sovereign-debt): Debt stock is the base; this node tracks the cost of carrying it.
Interest rates (indicator:interest-rates): Policy and market rates feed the interest bill with a lag as debt is refinanced.
U.S. 10Y and 30Y yields and velocity (indicator:us-10y-30y-yields): 10-year yield near 5% versus a roughly 3.5% average rate on the stock is the refinancing gap.
Fiscal-risk premia (indicator:fiscal-risk-premia): A rising interest burden can raise the premium investors demand, which raises the burden again.
Global bond markets (market:global-bonds): Sovereign bond yields across the US, euro area, UK and Japan are the price of new debt.
ECB (actor:ecb): Raised the deposit rate to 2.50% and is shrinking APP/PEPP holdings, adding to euro area refinancing costs.
France (country:france): Interest charges projected to rise from €79.2 billion (2026) to €91.2 billion (2027) with debt near 119% of GDP.
Italy (country:italy): Euro area's largest interest bill in this file (€87.2 billion in 2025) with debt near 137-140% of GDP.
United Kingdom (country:united-kingdom): Index-linked gilts make UK debt interest jump with RPI; £110 billion in 2025-26.
Japan (country:japan): Record ¥16.6 trillion interest request as the assumed rate rises from 3.0% to 3.8%.
JGBs (market:jgb): JGB yields near 30-year highs set the rate at which Japan's debt rolls over.
Why it matters now
The interest bill is rising in every large advanced economy at once. In the US, CBO counted $1,052 billion of net interest in the first 11 months of FY2026, up 12% and well above defense outlays of $833 billion. CBO's own baseline from February already had net interest above defense in 2026. Market yields have since moved above that baseline: the 10-year par yield was 5.24% on 2026-10-01 and 4.96% on 2026-10-22, against CBO's assumption of about 4.3%. CBO's October scenario shows what a sustained 1.5-point gap does: $6.0 trillion more in deficits over 2026-2036 and debt at 133% of GDP instead of 120%.
The mechanism is refinancing. The average rate on US marketable debt is about 3.5%, well below current yields, and about one-third of the debt matures within a year. Each auction replaces cheaper old debt with dearer new debt, so the bill keeps rising even if yields stop climbing. Japan's Ministry of Finance makes the same point: the effective rate on its stock rises only gradually, but its FY2027 interest request is a record ¥16.6 trillion on an assumed 3.8% rate, up from 3.0%. In the UK the channel is partly inflation: index-linked gilts added £4.0 billion to September's £10.9 billion debt-interest bill after RPI rose.
In Europe, Eurostat's 2026-10-21 release shows the euro area deficit steady at 3.0% of GDP while debt climbed to 87.7% in 2025 and 88.8% by mid-2026. The ECB raised its deposit rate to 2.50% in September and is letting its bond holdings run off, so more debt must be placed with private buyers. France expects public interest charges to rise by about €12 billion to €91.2 billion in 2027, and Italy paid €87.2 billion in 2025. The interest burden is therefore a slow-moving but compounding pressure on budgets: it crowds out other spending, and it can feed back into risk premia if markets doubt a country's ability to stabilise its debt ratio.
Risks and open questions
Bull case: The burden is rising but remains manageable for most large issuers. Average rates on existing debt lag market yields, which gives governments years to adjust. Japan's Ministry of Finance notes that nominal growth exceeded the effective interest rate in FY2023-24, which pushed the debt ratio down. Italy runs a primary surplus of 0.8% of GDP, and the euro area deficit has held at 3.0%. If inflation from the energy shock fades, inflation-linked interest falls back too, and central banks would have room to stop tightening. The US 10-year yield fell to 4.96% on 2026-10-22 from 5.24% on 2026-10-01, a reminder that yields can retreat. Inference (AA): in this path, interest-to-GDP rises slowly toward the CBO baseline of 4.6% by 2036 rather than the high-rate scenario, and budget plans such as France's €54 billion adjustment and Italy's surplus slow the debt ratio's climb.
Bear case: The refinancing gap is large and the lag cuts both ways: even if yields stop rising, the interest bill keeps climbing as old cheap debt matures. US yields are well above the 4.3% CBO assumed; CBO's +150 basis point scenario adds $6.0 trillion to deficits by 2036. The UK pays debt interest of about £110 billion a year, and its 10-year gilt yield is the highest in the G7, per the OBR. France is running a deficit above 5% while interest charges rise by about €12 billion in one year. Japan's interest request jumped about ¥3.6 trillion in a single budget cycle. The ECB is no longer reinvesting maturing bonds, so private buyers must absorb more supply. Inference (AA): when r rises above g, a government needs a bigger primary surplus just to keep its debt ratio flat; if politics cannot deliver that, higher risk premia can raise r further, the feedback loop the OBR calls an 'extremely steep' trajectory in its debt-interest feedback scenario.
Falsifiers: - The rising-burden view weakens if US 10-year yields fall back toward the 4.3% CBO assumed and stay there through 2027, closing the refinancing gap. - It weakens if US net interest growth for FY2027 (CBO monthly reviews) slows below the 12% pace of FY2026. - It weakens if Eurostat's April 2027 notification shows the euro area debt ratio falling from 87.7% of GDP. - It weakens if the OBR's 2026-10-28 forecast lowers UK debt interest relative to the March 2026 forecast. - It weakens if Japan's final FY2027 budget assumes an interest rate below the 3.8% requested. - The benign view fails if France's 2027 interest charges exceed the €91.2 billion projected while its deficit stays above 5% of GDP. - The benign view fails if CBO or Treasury data show net interest exceeding Social Security or Medicare outlays earlier than CBO's baseline implies.
Value accrual gate: Not a crypto asset. A higher interest burden transfers income from taxpayers and other budget lines to bondholders; new buyers of government debt gain higher yields while holders of older, low-coupon bonds and governments needing to refinance lose.
What to watch
OBR Economic and fiscal outlook and UK Budget, with a new debt-interest forecast. (2026-10-28); Source: obr.uk
ONS public sector finances for October 2026, including RPI-driven index-linked interest. (2026-11-20); Source: ons.gov.uk
CBO Monthly Budget Review for October 2026, the first month of FY2027 net interest data. (by 2026-11-15); speculative, no scheduled source
US Treasury quarterly refunding: borrowing estimates and coupon auction sizes for early FY2027. (early 2026-11 (not verified)); speculative, no scheduled source
Japan's FY2027 budget draft and its final assumed interest rate (request: 3.8%). (around 2026-12 (not verified)); speculative, no scheduled source
Eurostat's next deficit and debt notification for the euro area and member states. (2027-04-21); Source: ec.europa.eu
AA inference
Inference (AA): The interest burden is the most mechanical part of the fiscal story, which makes it useful for the graph. It links debt stocks to bond yields through a known lag, so AA can watch the gap between the average rate on each country's debt (about 3.5% in the US) and current market yields (near 5% for the US 10-year) as a forward indicator of budget pressure. AA feeds the US interest-to-spending ratio into its Productive Debasement Score and, in this broadened node, compares the same pressure across the euro area, France, Italy, the UK and Japan. AA treats a widening yield-versus-average-rate gap, faster RPI-driven UK interest jumps, and record Japanese interest requests as evidence of rising pressure, not as a prediction of crisis or of any asset-price move.
Sources
CBO Monthly Budget Review for September 2026 (2026-10-08): the federal deficit for fiscal year 2026 was an estimated $2.0 trillion, $218 billion more than in FY2025; revenues rose $169 billion (3%) and outlays rose an estimated $386 billion (6%), with net interest among the categories that increased. (Source: cbo.gov, accessed 2026-10-23)
CBO Monthly Budget Review for August 2026 (2026-09-09): in the first 11 months of FY2026, net interest on the public debt was $1,052 billion, up $111 billion (12%) from $941 billion a year earlier, because the debt was larger and long-term interest rates were higher, partly offset by lower short-term rates. (Source: cbo.gov, accessed 2026-10-23)
In the same 11 months, CBO put Department of Defense military outlays at $833 billion and Social Security benefits at $1,514 billion. (Source: cbo.gov, accessed 2026-10-23)
CBO Monthly Budget Review for June 2026 (2026-07-09): in the first nine months of FY2026, net interest on the public debt was $857 billion (up $98 billion, 13%), Department of Defense military outlays $677 billion and Social Security benefits $1,233 billion. (Source: cbo.gov, accessed 2026-10-23)
CBO's February 2026 baseline projects net interest of $1,039 billion in 2026 (3.2% of GDP in its summary table; the narrative says 3.3%) and $2,144 billion (4.6% of GDP) in 2036; in 2026 net interest exceeds defense (2.9% of GDP), and by 2036 it exceeds Medicare (4.2%). (Source: cbo.gov, accessed 2026-10-23)
CBO's Director's statement (2026-02-11) projects debt held by the public rising from about 99% of GDP at the end of 2025 to 120% in 2036, surpassing the 1946 record of 106% in 2030, with the 10-year Treasury yield assumed to rise from 4.1% in 2025 Q4 to 4.3% in 2027 Q4. (Source: cbo.gov, accessed 2026-10-23)
CBO, 'Projections of Deficits and Debt Under Two Scenarios With Higher Interest Rates' (2026-10-08): if the 10-year rate averaged 5.8% instead of the baseline 4.3% (+150 basis points), cumulative 2026-2036 deficits would be $6.0 trillion larger and debt held by the public would reach 133.1% of GDP in 2036 instead of 120.2%; at +50 basis points the deficits would be $1.9 trillion larger and debt 124.4%. (Source: cbo.gov, accessed 2026-10-23)
The Joint Economic Committee (Republican staff) said on 2026-08-20 that total public debt had hit a record $40.047 trillion; the release does not state the as-of date. (Source: jec.senate.gov, accessed 2026-10-23)
A JEC issue brief of 2026-10-14, citing Treasury Fiscal Data, puts total debt at the end of FY2026 at $40.2 trillion, of which $32.4 trillion held by the public, and the average interest rate on marketable debt at about 3.5% with an average maturity of about 70 months; it says about one-third of the debt (about $10 trillion) matures within a year. (Source: jec.senate.gov, accessed 2026-10-23)
Treasury's August 2026 refunding presentation to TBAC put the Treasury bill share of marketable debt at 22.2% as of 2026-07-31 and projected $713 billion of coupon securities maturing in July-September 2026 and $748 billion in October-December 2026. (Source: home.treasury.gov, accessed 2026-10-23)
Treasury daily par yield curve: the 10-year yield was 4.19% on 2026-01-02, 5.24% on 2026-10-01 and 4.96% on 2026-10-22; the 3-month bill was 3.65%, 4.17% and 4.22% on the same dates. (Source: home.treasury.gov, accessed 2026-10-23)
Eurostat (2026-10-21): in 2025 the euro area (EA20) government deficit was 3.0% of GDP, unchanged from 2024, and government debt rose to 87.7% of GDP from 86.6%; expenditure was 49.8% of GDP and revenue 46.8%. (Source: ec.europa.eu, accessed 2026-10-23)
Eurostat (2026-10-21): the highest 2025 debt ratios were Greece 145.4%, Italy 136.7%, France 115.7%, Belgium 108.1% and Spain 100.5%; the highest deficits were Romania 7.8%, Poland 7.2%, Belgium 5.2% and France 5.1% of GDP. (Source: ec.europa.eu, accessed 2026-10-23)
Eurostat quarterly debt (2026-10-21): euro area government debt was 88.8% of GDP at end-Q2 2026 (provisional), after 88.4% at end-Q1 2026 and 87.3% at end-Q2 2025; debt securities were 84.5% of the total. (Source: ec.europa.eu, accessed 2026-10-23)
Eurostat Statistics Explained (data extracted 2026-04-22): property income paid, mostly interest, was 3.8% of general government expenditure in the euro area in 2025; among EU states the highest shares were Hungary 8.0%, Italy 7.6%, Romania 6.6%, Greece 6.5% and Spain 5.3%. (Source: ec.europa.eu, accessed 2026-10-23)
The ECB raised its three key rates by 25 basis points on 2026-09-10, taking the deposit facility rate to 2.50% from 2026-09-16, and said the APP and PEPP portfolios are shrinking as maturing principal is no longer reinvested. (Source: ecb.europa.eu, accessed 2026-10-23)
In her IMFC statement of 2026-10-17, President Lagarde said euro area headline inflation rose to 3.8% in September, that long-term interest rates had risen notably, that 'fiscal sustainability remains a crucial anchor', and that high-debt countries should consolidate and re-prioritise spending. (Source: ecb.europa.eu, accessed 2026-10-23)
ONS (2026-10-21): UK central government debt interest payable was £10.9 billion in September 2026, up £1.6 billion on a year earlier and £2.0 billion above the OBR forecast; £4.0 billion of it was the capital uplift on index-linked gilts, mainly from a 0.6% rise in RPI between June and July. (Source: ons.gov.uk, accessed 2026-10-23)
ONS (2026-10-21): UK debt interest was £60.8 billion in the financial year to September 2026 (up 3.7%); public sector net borrowing was £97.8 billion (£6.0 billion above the OBR forecast); public sector net debt was £3,005.0 billion, or 94.0% of GDP. (Source: ons.gov.uk, accessed 2026-10-23)
OBR Fiscal risks and sustainability (2026-07-07): UK debt interest of £110 billion in 2025-26 is the third-largest area of public spending after health and welfare and has more than doubled as a share of GDP since just before the pandemic; the average effective nominal yield on government debt was about 1.75% in 2012-2019 and 4.5% in 2025; UK 10-year gilt yields are the highest in the G7; adding a feedback from higher debt to higher interest rates produces an 'extremely steep upward trajectory' for debt. (Source: obr.uk, accessed 2026-10-23)
OBR's long-term baseline assumes the growth-corrected interest rate (r minus g) converges to about 0.5 percentage point; excluding world wars, its long-run average has been between zero and 0.5 point. (Source: obr.uk, accessed 2026-10-23)
OBR ready reckoner (March 2025 forecast): a 1-point rise in RPI inflation adds about £9.9 billion to UK debt interest in 2028-29, a 1-point rise in gilt rates about £9.6 billion, and a 1-point rise in short rates about £4.9 billion. (Source: obr.uk, accessed 2026-10-23)
INSEE (2026-05-29): French general government interest charges were €64.7 billion in 2025, up 11.2% from 2024, because both the debt stock and the average rate on OATs rose since 2022; the deficit was €152.5 billion (5.1% of GDP) and debt 115.7% of GDP. (Source: insee.fr, accessed 2026-10-23)
French Council of Ministers report (2026-10-01): public interest charges are projected to rise from €79.2 billion in 2026 to €91.2 billion in 2027; the 2026 deficit forecast is revised to 5.4% of GDP, debt to 119.3%, and the 2027 state issuance ceiling is €340 billion (from €310 billion); the 2027 budget includes a €54 billion adjustment (€43 billion new measures, €11 billion already in place). (Source: info.gouv.fr, accessed 2026-10-23)
Agence France Trésor: state budget debt service (charge de la dette) is revised to €62.6 billion for 2026 (initial budget €59.3 billion) and set at €72.9 billion for 2027; the weighted average yield on medium- and long-term issues was 3.55% in 2026 to date versus 3.14% in 2025. (Source: aft.gouv.fr, accessed 2026-10-23)
Italian Chamber of Deputies dossier on the DPFP 2026 (2026-10-06): interest expenditure was €87.2 billion in 2025, the primary surplus rose to 0.8% of GDP (0.5% in 2024), and the long-term rate assumption is about 3.9% (2026), 4.3% (2027), 4.4% (2028) and 4.5% (2029), around 30 basis points above April's assumptions for 2027-2029. (Source: documenti.camera.it, accessed 2026-10-23)
Japan's Ministry of Finance (2026-08-28): the FY2027 request for national debt service is ¥36.64 trillion, up ¥5.36 trillion from the FY2026 initial budget, of which interest and discount charges are ¥16.59 trillion (FY2026: ¥13.04 trillion). (Source: mof.go.jp, accessed 2026-10-23)
MOF Fiscal System Council material (2026-09-30): the FY2027 interest-cost request of ¥16.6 trillion is a record and assumes a 3.8% rate, versus ¥13.0 trillion at 3.0% in the FY2026 budget; ordinary JGBs outstanding exceed ¥1,000 trillion; the effective rate on the stock rises only gradually as higher-rate bonds replace maturing low-rate ones. (Source: mof.go.jp, accessed 2026-10-23)
The same MOF material says Japan's debt-to-GDP ratio fell in FY2023-24 partly because nominal growth exceeded the effective interest rate, and that the interest-rate factor will increasingly push the ratio up. (Source: mof.go.jp, accessed 2026-10-23)
Finance Minister Katayama said on 2026-09-04 that the long-term JGB yield had risen to about 3%, its highest in roughly 30 years, that rising rates increase the government's interest burden, and that the ministry watches the market 'with a very high sense of tension'. (Source: mof.go.jp, accessed 2026-10-23)