Japan's Debt Reckoning Arrives as Bond Yields Break the 3% Barrier

Japan's 10-year government bond yield broke through the 3% threshold on September 1 for the first time since 1996, ending three decades of near-zero borrowing costs and raising fresh questions about the sustainability of the country's ballooning public finances.

The yield — known in Japan as the long-term interest rate and described by Nikkei as "the economy's thermometer" — rose to 3.005% by the close of trading on September 1, its highest in 30 years, before climbing further to 3.015% on September 2. It serves as the primary benchmark for long-term borrowing costs across the economy, influencing fixed-rate mortgages, corporate bonds, and long-term business lending. The rate then retreated to around 2.895% by September 4.

Three forces converged to drive the yield above 3%. Japan's government ministries submitted their fiscal 2027 budget requests totaling approximately 143.1 trillion yen — a record high. While the actual bond issuance will be considerably smaller, markets interpreted the figure as a signal of continued fiscal expansion, prompting investors to demand higher yields as compensation for the expected increase in government debt supply.

Simultaneously, the Bank of Japan has been signaling its intent to raise interest rates, unwinding years of ultra-loose monetary policy that kept yields artificially low. A weakening yen — hovering near 160 to the dollar — combined with elevated energy costs linked to Middle East tensions, has also stoked imported inflation and added further justification for tighter monetary policy.

Japan's domestic price pressures remain contained for now. Tokyo's core consumer price index for August, which excludes fresh food, rose just 1.8% — below the Bank of Japan's 2% target for the seventh consecutive month. What the central bank is managing, analysts note, is not runaway inflation but an upside risk that has not yet fully passed through to consumer prices.

The fiscal math is growing uncomfortable. Japan's fiscal 2027 budget request allocates 36.64 trillion yen to debt servicing — a record — of which roughly 16.59 trillion yen covers interest and discount charges alone. Put differently, for every eight yen the government plans to spend, more than one goes directly to paying interest.

That figure is calculated using an "assumed interest rate" — an internal planning rate set at 3.8% for fiscal 2027, the highest since 1998. Finance Ministry officials told Nikkei that if the long-term rate remains near 3%, the assumed rate may need to rise to 4% when the formal budget is finalized in December, pushing interest costs still higher.

The dynamic forms a self-reinforcing loop: larger spending plans unsettle bond markets, which push yields higher; higher yields inflate interest payments, leaving less room to actually govern; and any attempt to fill the gap by borrowing more only restarts the cycle. Nikkei framed the overarching risk with a "yellow light" warning — can Japan's nominal economic growth outpace its rising interest costs?

Japan's government bonds are held primarily by three groups: the Bank of Japan itself (the largest holder after years of yield-curve control purchases), regional and city banks that channel depositors' savings into bonds, and life insurers and pension funds seeking stable long-term returns. In practice, a large share of Japan's household savings and retirement assets are lent to the government through these institutions.

The September 1 auction results were mixed. The bid-to-cover ratio improved from the previous auction and the highest accepted yield hit a 30-year record, but the lowest accepted price came in below market expectations. A regional bank executive told Nikkei the pace of the move was "too fast" and "troubling," noting that the institution's existing bond holdings were losing value. A foreign securities firm bond trader added that even at 3%, the yield may not adequately compensate for the underlying fiscal risk.

By September 4, the 10-year yield had pulled back to approximately 2.895% — a counterintuitive result. When markets trust a central bank to raise short-term rates and keep inflation in check, long-term yields can actually fall, because investors believe future price pressures will be contained. The retreat was reinforced by news that Finance Minister Katayama would remain in post, reducing concerns about fiscal management continuity, and by a concurrent decline in U.S. long-term yields.

External pressure played a role as well. U.S. Treasury Secretary Scott Bessent told Reuters on August 30 that Abenomics — Japan's long-running monetary stimulus strategy — may have run its course, without prescribing a specific course for the Bank of Japan. A subsequent U.S. Treasury statement confirmed American support for Japan's use of "market and monetary policy tools" to address "excessive yen depreciation," a phrase markets read as Washington's endorsement of faster Bank of Japan rate hikes. Bessent made the remarks the same day he met with Bank of Japan Governor Kazuo Ueda on the sidelines of the G20.

Nomura Securities chief market economist Yasuhei Okazaki offered a measured interpretation: if Japan sustains 2% inflation, a long-term rate near 3% is not unusual. His formula — 2% inflation plus roughly 0.5% long-term growth potential plus a normal term premium — adds up to approximately 3%. Under this reading, Japan is simply rejoining the community of economies where capital carries a cost.

Critics focused less on the level than on the trajectory and the reason behind it. The regional bank executive and the foreign bond trader both expressed concern not about 3% itself, but about whether the speed of the rise and the fiscal backdrop can sustain it as a stable equilibrium. The same yield level, Nikkei noted, carries entirely different implications depending on whether it reflects genuine economic recovery or investor anxiety about government solvency.

Original Article In Chinese

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