RECEIVING TRANSMISSION…研究ノート / RESEARCH NOTE 002 · REVIEWED 2026-09-08
Two agreements, an asset bubble, a long repair and a global trade. Connected episodes—with different causes. A source-led history, not an argument that a token must replace the yen.
01 · 1985
The Plaza Accord was a response to international imbalances and protectionist pressure. On 22 September 1985, five countries supported an orderly rise of major non-dollar currencies against the dollar. Japan participated in this coordination; it was not an agreement to abolish Japan’s monetary choices.
A stronger yen has uneven effects. Exporters receive fewer yen for a given dollar receipt; importers can buy dollar-priced goods more cheaply. The impact also depends on pricing, imported inputs and hedging. That tension helps explain why authorities worried about an appreciation-driven slowdown, without making every rise of the yen inherently harmful.
02 · 1986–1988
Japan cut its discount rate five times in 1986–1987. The Louvre communiqué of February 1987 shifted the emphasis toward exchange-rate stability and stronger domestic demand in surplus economies; it explicitly recorded a further half-point Japanese discount-rate cut. These were changing policy responses, not a perpetual zero-rate treaty.
Foreign pressure was real. In his 2000 retrospective, BOJ policy board member Kazuo Ueda identified pressure to maintain low rates in the 1987 and 1988 Reagan meetings with Nakasone and Takeshita. He also discussed yen appreciation and the 1987 stock crash. This supports a historically specific pressure claim. It does not establish that fear of present-day carry unwinds explains decades of Japanese policy.
03 · LATE 1980s
BOJ researchers identify a combination of prolonged easing, financial deregulation, aggressive lending, weak risk management, land incentives and optimism. An interest-rate cut alone is not a sufficient explanation of the bubble.
The collateral loop explains the amplification: higher land prices support larger loans, loans finance more property purchases, and purchases validate higher valuations. Rising collateral is not the same as rising productive cash flow. When lenders assume both are equivalent, a reversal can expose losses across borrowers and banks at once. This is a mechanism, not a claim that every Japanese loan followed it.
04 · 1989–1990 / THE SCALE OF THE BOOM
The numbers explain the metaphor. At the land-price peak in 1990, Japan’s total land valuation was reported at roughly four times that of the United States. Major overseas acquisitions also made Japanese purchasing power visible. Stock prices had already peaked at the end of 1989; the land and stock peaks were not simultaneous.
But a valuation is not a national bank balance. Owners cannot all sell at the last quoted price without changing the market. Debt, ownership, exchange rates and willing sellers also matter. The historically defensible claim is that Japanese asset valuations and overseas corporate buying were extraordinary—not that Japan possessed enough liquid cash to purchase an entire sovereign country.
01 · 1990 · REPORTED ESTIMATE
Total land market value · United States = 1 · linear scale starting at zero
02 · NIKKEI 225 · THREE OBSERVATIONS
Index points · common scale 0–40,000 · values rounded as reported
1985 → 1989: about 3.09× · 1989 → 1992: about −63.2%
03 · 1989-11 · ACTUAL ACQUISITION
≈ US$3.4bn
Sony’s 1991 annual report records approximately $3.4 billion for all outstanding common shares of Columbia Pictures Entertainment in November 1989. A major US business was acquired; the United States itself was not for sale.
Sony · Annual Report 1991 · Acquisitions ↗05 · 1990s
Monetary tightening and restrictions on real-estate lending preceded the collapse of the boom. Falling collateral left banks with bad loans and borrowers with debt that did not fall alongside their assets. Weak recognition and resolution of losses prolonged the banking problem. The Lost Decade describes prolonged underperformance; it does not mean output fell in every year or that all of Japanese society stopped developing.
Consider a firm whose assets fall from 100 to 60 while debt stays at 80. Its net worth changes from +20 to −20. A cheaper new loan may not induce expansion: the firm may first repay debt. A bank worried about capital may also restrict credit. This illustrative arithmetic explains why repairing balance sheets and stimulating new spending are different tasks.
06 · 1999–2024
Persistent demand weakness, changing growth prospects and demographics belong in the explanation of the later low-rate environment. The BOJ’s 2025 retrospective also stresses slow adaptation and entrenched wage-and-price behavior. Aging is not a mechanical rule that always lowers rates; its effects depend on saving, investment and other conditions.
The policy sequence matters: zero interest rates in 1999, quantitative easing in 2001, QQE in 2013, and negative rates and yield curve control in 2016. Negative rates applied to part of banks’ BOJ balances, not every household deposit. In March 2024 the BOJ ended negative rates and the YCC framework. These historical dates should not be presented as today’s policy-rate quotation.
Low nominal rates do not guarantee easy real financing. As an approximation, expected real interest equals nominal interest minus expected inflation. At 0% nominal interest and −1% expected inflation, the real rate is about +1%. Weak demand and deflation can therefore coexist with apparently very cheap money.
07 · MECHANISM / 2024
An unhedged yen carry trade funds a foreign-currency asset with yen borrowing. The investor earns an asset return but owes yen. If the yen strengthens, the foreign proceeds buy fewer yen at repayment. Hedging changes this exposure and has a cost; it does not simply preserve an unhedged interest spread for free.
BIS researchers describe the August 2024 turbulence as a macro-news shock amplified by leveraged unwinds and margin pressures, including yen carry trades. It was not evidence that all Japanese foreign assets were being sold. BIS also warns that available borrowing statistics do not identify every borrower’s purpose, so a precise global carry total cannot be read from Japan’s Treasury holdings.
08 · EVIDENCE / LIMITS
Japan issuing JGBs, the BOJ reducing JGB purchases, Japan’s reserve manager selling US Treasuries, and a private fund unwinding a carry trade are four different operations. Japan’s Finance Minister decides official FX intervention; the BOJ acts as agent. Neither that division nor private carry exposure establishes a US veto over Japanese monetary policy.
A large Treasury sale could affect bond prices and yields, depending on market depth and other buyers. That creates a plausible interest in orderly markets, not proof of a sales ban. Selling a dollar bond also does not necessarily mean buying yen: the seller can retain dollar cash. The currency conversion is a separate step.
In May 2025, Finance Minister Kato clarified that his negotiation-card remark concerned commenting that Japan would not casually sell Treasuries, rather than proposing to sell its holdings. This is a public record of diplomatic messaging. The sources reviewed here do not establish a general US prohibition on sales, or a permanent low-rate pact motivated by fear of a carry unwind.
09 · EDITORIAL / NOT A HISTORICAL CONCLUSION
Digitizing a yen claim can improve payment infrastructure while leaving its unit of account in yen. That is a useful distinction, not evidence that yen stablecoins are pointless. Nor does this history prove that a fixed-supply token preserves purchasing power or that moving into YAN is the rational outcome.
Bank of Yan proposes ¥EN → ¥AN as a direction: carry the cultural character forward, make the rules readable, and build participation around public records. YAN is a community token project with a fictional bank identity. Its progress should be judged through contributions, working features and verifiable money flows. Market, liquidity, contract and operator risks remain.
YAN is an independent community satire project. Not affiliated with or endorsed by Hyperliquid Labs, the Government of Japan, the Bank of Japan, or the U.S. Government.
Bank of Yan · 2026 · A fictional institution. Not a bank.
