USA vs Japan — Debt to GDP
Same ratio, different risk — it depends on who holds it.
Japan’s general-government gross ratio (≈262%, IMF basis) is more than double the US gross federal ratio (≈130%, incl. intragovernmental holdings), yet over 85% of Japanese bonds are held at home and the Bank of Japan absorbs roughly half. About 30% of the publicly held US Treasuries, by contrast, sit with foreign investors and central banks, tying the currency and rate path to global capital markets. It is holder structure, not the ratio, that separates the two.
| Country / Series | Debt / GDP | Household / GDP | GDP (T USD) | Debt (T USD) | Note |
|---|---|---|---|---|---|
| USA (federal, gross) | 129.6% | — | 31 | 40 | incl. intragovernmental; ≈30% of the public share held abroad |
| Japan (general gov, gross) | 262.0% | — | 4.09 | 11 | 85%+ domestically held; BoJ ≈ half |
| Japan (net, IMF basis) | 155.0% | — | 4.09 | 6.34 | net of general-gov financial assets |
Who holds the bonds
Japan is at 262% of GDP, the United States at 122%. On the numbers alone Japan looks more than twice as risky. Look at the funding structure, though, and the assessment is not that simple. More than 85% of Japanese government bonds are held domestically, with the Bank of Japan holding roughly half of that. About 30% of US Treasuries are held abroad.
A high domestic share lowers the risk of a sudden yield spike caused by capital flight, because the seller and the buyer sit inside the same economy. A high foreign share, conversely, lets geopolitical variables or conditions in the holder's own country feed into domestic yields.
So the simple ranking "the higher ratio is the riskier" does not hold. Absorbing 262% domestically and sustaining 122% with 30% external dependence are two different kinds of vulnerability.
How central bank holdings change the arithmetic
Government bonds held by the Bank of Japan are formally government liabilities, but the interest ultimately flows back to the treasury and maturing holdings are largely repurchased. On a consolidated view, it is defensible to read that portion as not a net burden on the government. This is part of what takes gross debt of 262% down to net debt of 155%.
The structure has a price, though. When a central bank holds a large stock of government bonds, normalising rates produces valuation losses and constrains the freedom of monetary policy. Raising rates in an inflationary phase increases both the government's interest bill and the central bank's losses at once, so the policy judgement becomes entangled with the fiscal position.
The US Federal Reserve also accumulated substantial Treasury holdings after quantitative easing, but ran them down comparatively quickly and never reached Japan's share. That difference lies behind the diverging paths the two countries took to normalising rates.
Maturity structure decides interest-rate sensitivity
Even at the same debt ratio, a shorter average maturity means a rate rise passes into the budget far faster. The more paper that has to be refinanced each year, the more the market rate simply becomes the government's funding rate. A long maturity, conversely, locks in yesterday's low rates for longer.
From this angle, what matters in comparing the two countries is not the stock but the annual refinancing volume and its weighted average maturity. It is entirely possible for a country with half the debt ratio to absorb a bigger interest-rate shock purely because its maturities are short.
The ratios in this table are therefore only a starting point. The actual size of the fiscal squeeze is set by the combination of ratio × average funding cost × refinancing speed, and looking at any one of these alone distorts the conclusion.
What this comparison implies for Korea
The United States and Japan present two different models for carrying high debt. America relies on the international standing of its currency; Japan on the depth of its domestic savings. Korea possesses neither asset.
Korea's strategy therefore has to be a third path: keeping the level of debt comparatively low while earning trust through external soundness and a record of fiscal discipline. This is not a preference but a conclusion derived from its conditions.
This perspective answers the question "the US is at 122% and Japan at 262%, so why is Korea's 46% a problem?" The issue is not the level of 46% but what mechanism holds that level and whether that mechanism is working right now. Comparing ratios is where that question starts, not where it ends.
The order to read this table in
First, check whether Japan is quoted gross or net. 262% and 155% are two different accountings of the same country. Second, remember that the US figure is federal and excludes state and local debt.
Third, read the composition of holders — domestic, foreign, central bank — alongside the ratio. Fourth, check the share of the budget taken by interest payments and the annual refinancing volume. Debt crises usually surface in cash flow before they surface in the stock.
Fifth, bearing in mind that both countries went through periods of heavy central bank bond holdings, read the boundary between monetary and fiscal policy together. Where raising rates moves the government's interest bill and the central bank's profit and loss at the same time, monetary decisions cannot rest on a judgement about prices alone.
Takeaway
The US leans on reserve-currency status and the deepest bond market in the world; Japan leans on domestic ownership and central-bank absorption. The shields differ in shape — neither is proof that the debt is “safe.” Read the structure, not the ranking.
Sources: US Treasury (debt held by public, TIC foreign holdings), IMF WEO Apr 2025 (gross/net, GDP), BoJ flow-of-funds. Figures provisional.