Working paper
Where Gabon’s debt is heading by 2030
Starting from the audit figure, we simulate the debt to 2030 under several assumptions, and show what weighs most on its path.
Abstract
Six findings
According to the audit published in September 2026, the State owed 9,524.6 billion FCFA at the end of 2025, or 68.9% of GDP. We start from this figure and simulate the debt to 2030, 20,000 times, varying growth, prices, oil, interest rates and the dollar. In every scenario tested, the debt rises again. These figures depend on our assumptions. They are not forecasts, and they do not measure the effect of an IMF programme.
The debt rises in every scenario. It would go from 68.9% of GDP at the end of 2025 to 74% at the end of 2026 and 79% at the end of 2027. In 2030, it would reach 92% with low-rate aid and fiscal effort, and 101% without them. Each year, between 73 and 77% of the simulated paths exceed the CEMAC ceiling of 70% of GDP, even with aid and effort.
Fiscal effort is the strongest lever, if it does little to slow growth. Improving the budget balance by 1 point of GDP a year from 2028 lowers the 2030 debt by 6.3 points. Low-rate aid lowers it by only 3.0 points. But if the effort slows growth, with a multiplier of 1, its effect falls to 3.1 points.
Debt appearing outside the deficit could weigh more than the effort. In the past, 4 to 7 points of GDP of debt appeared each year without going through the deficit. If this continued at half that pace, the 2030 debt would be 10 points higher. At the past pace, it would reach 113% of GDP.
Late payments exceed those in the debt bulletin, and they are rising. A government circular, quoted by Reuters, counts 1,094.6 billion of arrears at the end of 2025 and 1,198.8 billion at the end of June 2026. If the part above the bulletin’s 459.5 billion is not in the audit figure, end-2025 debt becomes 71.4 to 73.5% of GDP, above the ceiling. The 2030 debt would be 3.7 to 5.6 points higher, and 11.2 points higher if arrears kept rising at the same pace.
Our method underestimated the debt in the past. Replayed on 14 editions of IMF forecasts, using only the data known at each date, it underestimates the debt by 21 points of GDP at three years and 35 points at five years. Almost all of the gap comes from debt appearing outside the deficit. Taking it into account halves the error.
Financing is the weak point. Each year, the State must borrow about 20% of GDP to repay what falls due and cover the deficit. If the external market closed in 2028 and 2029, 2,538 to 4,280 billion of payment arrears would have to build up. Interest would go from 487.6 billion in 2026 to 926 billion in 2030 with aid and effort, and to 1,187 billion without them.
Keywordspublic debt · debt sustainability · Monte-Carlo simulation · stock-flow adjustments · backtest · CEMAC · Gabon
Methods
How we simulate the debt
Every number in the paper is written by a script from the archived sources. A check runs the calculations twice and confirms the results are identical.
The principle. Each year, the debt grows by the deficit and by the late payments settled by borrowing, and moves with the dollar. GDP moves with growth, prices and oil. Part of the debt is repaid each year and borrowed again at the current rate. These quantities are not known in advance, so we draw them 20,000 times from their past variations, starting from the 2026 budget and the 2027 budget bill. The text gives the middle value; the tables also give the range that holds eight paths out of ten.
The scenarios. Without aid or effort, the balance excluding interest follows the 2027 budget bill and the State borrows at market prices. With aid and effort, the State receives 600 billion of aid a year from 2027 to 2029 at 3.5%, borrows 1.5 points cheaper on the markets, and improves its balance by 1 point of GDP a year from 2028, up to +1.5% of GDP. Only the 2027 aid amount appears in a document; the rest are our choices. Every scenario uses the same 20,000 draws, so the gaps between them come only from the assumptions.
What the base model assumes, then relaxes. Fiscal effort has no effect on growth, the State always finds lenders, and no debt appears outside the deficit. Three extensions lift these assumptions one at a time, as scenarios: a multiplier from 0 to 1.5; four financing strains (a risk premium that rises with debt, higher world rates, the external market closed in 2028 and 2029, a restructuring in 2028); and debt appearing outside the deficit at half or all of its past pace.
The test on the past. The method is replayed on 14 starting years, drawn from 37 editions of the IMF World Economic Outlook (April 2008 to April 2026), with only the data known at each date, and compared with what was later observed, with the IMF’s own forecasts and with a constant ratio.
Results
In four numbers
Debt as a share of GDP in 2030, middle value of 20,000 paths.
92%
with low-rate aid and fiscal effort from 2028. Eight paths out of ten lie between 50 and 150%.
101%
with no aid and no effort.
113%
with aid and effort, if debt kept appearing outside the deficit at the past pace.
35 pts
underestimate of the debt at five years when the method is replayed on past IMF forecasts.
Keep in mindThese gaps come from the model. Aid after 2027, its rate and the fiscal effort are our assumptions, not known commitments. The effect of the effort on growth cannot be measured for Gabon: we test it separately. Social costs are not estimated. The starting figure itself is known only through the press, and its content is not detailed.
For the decision
What each choice changes
From the box and the table of the paper’s second section.
Prepare the 2027 budget on the assumption that the debt rises. Sustained fiscal effort slows this rise, all the more if it weighs little on growth. It is not enough if debt keeps appearing outside the deficit, as in the past. Before relying on a margin below the CEMAC ceiling, ask for a table that links the audit figure to the debt bulletin figure and to the late payments, then, every year, a table that explains the gap between the deficit and the rise in debt. Prepare the financing too: the State must borrow about 20% of GDP each year.
| Choice | What it requires | Effect on the 2030 debt |
|---|---|---|
| Improve the budget balance from 2028 | 1 point of GDP a year, up to +1.5% of GDP | 6.3 points lower, or 3.1 if the effort slows growth (multiplier of 1) |
| Obtain low-rate aid | 600 billion a year from 2027 to 2029, at 3.5% | 3.0 points lower |
| Limit the aid to 2027 | A single year of aid | 0.6 point higher than three years of aid |
| Pay the late payments in two years | 29 billion more interest over five years | 0.2 point higher |
| Stop new late payments | Pay when due, and publish the detail of arrears | Avoids 5.6 points more if the circular’s arrears kept rising |
| Stop debt appearing outside the deficit | Link the deficit to the rise in debt every year, and explain the gap | Avoids 10 to 21 points more (half or all of the past pace) |
With the paper
Note and simulator
Released with the paper on 17 October 2026, updated on 21 October with the text of the 2027 budget bill and the arrears circular.
- Which figure should be used for Gabon’s debt? (2 pages, English, 21 October 2026)
Decision note. Which end-2025 figure to start from, what each choice changes, and the table to ask for before relying on a margin below the CEMAC ceiling. - Quel chiffre retenir pour la dette du Gabon ? (2 pages, French, 21 October 2026)
The same decision note in French. - Gabon debt simulator
The model of the study, open to your own assumptions: fiscal effort, aid, borrowing costs, late payments, effect on growth and debt appearing outside the deficit.
References
Main sources
The paper cites 23; the full list, with links, is in the PDF.
- IMF. Press release, IMF Staff Concludes Visit to Gabon, 26 September 2026.
- Gabonreview. Dette publique : l’audit efface plus de 2 175 milliards de FCFA de l’estimation initiale (in French), 15 September 2026.
- Gabon Media Time. La dette publique officiellement arrêtée (in French), 15 September 2026.
- Gabonreview. Dette publique : le Gabon doit 8 780 milliards de FCFA à fin décembre 2025 (in French), 17 July 2026.
- World Bank. Gabon Public Finance Review 2026, September 2026.
- IMF. Gabon: 2024 Article IV Consultation, Country Report No. 24/144, May 2024.
- Gabon Media Time. Financing of the 2027 budget bill, and debt interest in the 2027 budget bill (in French), 22 and 24 September 2026.
- Ecomatin. Budget support sought in 2027 (in French), 22 September 2026.
- IMF. World Economic Outlook, editions of April 2008 to April 2026, used for the backtest.
- Gabonese Republic. 2027 budget bill, text of 26 September 2026 (in French).
- Sika Finance. Les arriérés de dette atteignent 1 198,8 milliards FCFA à fin juin 2026 (in French), 20 October 2026.
Hodologic Research (2026). Where Gabon’s debt is heading by 2030. 17 October 2026, 32 pp.