Japan’s currency has fallen to its weakest level in four decades against the dollar, a puzzling development given that the Bank of Japan has raised interest rates to their highest point in more than 30 years. The divergence highlights the unusual bind Japan finds itself in as it tries to normalize monetary policy after years of ultra-loose settings.
In most economies, rising interest rates tend to attract foreign capital and push a currency higher. Japan is defying that pattern. The yen has slid to a 40-year low against the dollar even as the Bank of Japan has lifted its benchmark rate to levels not seen since 1993. For investors and policymakers watching Asia, the dynamic signals how deeply entrenched Japan’s structural challenges have become.
The explanation begins with what economists call the interest rate differential — the gap between what investors can earn in Japan versus other major economies. Even at a 31-year high, Japan’s rates remain far below those in the United States and Europe. That gap makes it more rewarding to hold dollars or euros than yen, putting persistent downward pressure on Japan’s currency regardless of what direction the Bank of Japan moves.
There is also the so-called carry trade to consider. For years, investors borrowed cheaply in yen and put that money to work in higher-yielding assets abroad. Even as the Bank of Japan tightens, those positions unwind slowly, and the yen’s weakness can persist long after the rate cycle turns.
A weaker yen is a double-edged reality for Japan. It makes exports from Japanese manufacturers more competitive abroad, which benefits large industrial companies. But it also drives up the cost of imported energy and food, squeezing household budgets at a time when inflation is already running above the Bank of Japan’s 2 percent target. That imported inflation complicates the central bank’s job: tightening too fast risks damaging a fragile domestic recovery, while moving too slowly lets prices stay elevated.
The Bank of Japan is also navigating political and market pressures that most central banks do not face. After decades of deflation — falling prices — the institution built its entire framework around preventing prices from falling too fast. Pivoting to fight inflation while also managing a currency in free fall requires a delicate balance that has few historical precedents in modern Japan.
Global investors are paying close attention. Japan is the world’s fourth-largest economy and the largest foreign holder of U.S. Treasury bonds. Sharp moves in Japanese rates or the yen can ripple through bond markets worldwide, affecting everything from mortgage rates in the U.S. to borrowing costs in emerging markets.
The Bank of Japan’s next policy meeting will be closely watched for signals on whether officials are willing to move more aggressively to stabilize the yen, or whether they will hold course and accept a weaker currency as the price of gradual normalization.
