Japan Is Back. Is Inflation the Reason?

The Nikkei stock index recorded last week its first new high in 34 years, a fitting tribute to Japan’s re-emergence as a genuinely exciting economy.

It also comes amid mounting evidence that Japan has finally broken the hold of deflation. Inflation in January was 2.2%, the 22nd month above 2%. Wage growth has picked up too.

This appears to vindicate the economic consensus that deflation was a primary driver of Japan’s decades long malaise. But that conclusion might be premature. Proof of deflation’s harm has been elusive, and the benefits of low, positive inflation might be similarly subtle.

Consumers are often surprised to hear that deflation is supposed to be bad. In the U.S., where prices have risen steeply since 2021 , normal people, and even economists, wouldn’t object if they fell a bit.

The trouble arises when prices fall persistently, year in and year out, because wages, incomes and the prices of assets such as property tend to follow. Debtors struggle to repay loans and might slash spending or default, endangering the financial system. That is what happened in the U.S. when prices fell 27% from 1929 to 1933.

Even mild deflation can, in theory, inhibit growth. Central banks stimulate spending by lowering nominal interest rates below inflation to make the real—i.e., inflation-adjusted—cost of borrowing negative. That is almost impossible when inflation is itself negative.

The roots of deflation

Japan’s deflation began after its property and stock-market bubbles burst in the early 1990s. Ensuing losses at banks eroded their ability to lend. Inflation turned negative in 1999.

Western economists such as future Federal Reserve Chair Ben Bernanke argued that curing deflation was essential to restoring Japan’s economic health. The Bank of Japan agreed, at first half heartedly and then wholeheartedly.

It used zero, then negative, short-term interest rates. Next came purchases of short-term, then long-term, government securities. Finally, the BOJ even bought shares in companies with newly created money to stimulate spending and raise inflation.

The BOJ only succeeded in bringing inflation up to around zero. It took the global supply chain shocks of the pandemic to finally push underlying inflation to 2%, the bank’s target .

Japan’s 25 years of zero to negative inflation was accompanied by one of the rich world’s lowest growth rates. Japanese deflation became a cautionary tale for other countries, most recently China, where prices are currently falling .

Yet proving that deflation was behind Japan’s problems is maddeningly hard. Arguably, it was more symptom than cause.

In the early 1990s, working-age population growth turned negative. This happened just as Japan’s post-World War II phase of catching up to other developed nations ended. Meanwhile, industry began moving production to lower-wage countries.

All this, plus the banking crisis, put structural downward pressure on prices, wages and growth.

Underlying performance

Adjusted for its shrinking population, however, Japan’s performance has been respectable. From 1991 to 2019, its output per hour worked rose 1.3% a year. This was slower than in the U.S. but comparable with Canada, France, Germany and Britain, and faster than Italy or Spain, according to the economists Jesús Fernández-Villaverde, Gustavo Ventura and Wen Yao.

Since 2019, output per working-age person rose 7% in the U.S., 5% in Japan, 2% in the eurozone and zero in Britain, by my calculations. (This might overstate Japan’s performance because many of its elderly still work.) As any visitor can attest, Japan remains a prosperous, harmonious and well-ordered place.

“Had you appointed me governor of the Bank of Japan for 25 years with all the power in the world, I don’t think I would have been able to do better,” said Fernández-Villaverde.

This doesn’t prove deflation was benign. Growth (and deflation) might have been worse without the BOJ’s herculean monetary efforts. And if inflation had been positive, growth might have been stronger.

Still, it raises an awkward question: If zero to negative inflation is so damaging, where is the evidence?

The price mechanism

The harm might lie in subtle behavioural changes by investors, companies and the public. For example, in a market economy, changing relative prices and wages are critical signals for reallocating capital and labor from stagnant to growing sectors.

Relative prices changes are unusually rare in Japan, according to the University of Tokyo economist Tsutomu Watanabe. He has found that from 1995 through 2021, prices of more than half of products didn’t change at all from year to year. This wasn’t just because average inflation was lower; price changes deviated from the average much less than in other countries.

In a December speech, Bank of Japan Governor Kazuo Ueda said years of low to negative inflation led to a “status quo in wage- and price-setting behaviour,” so many prices and wages didn’t change. “The know-how for raising prices was thus lost,” he said.

The absence of this price-discovery function, Ueda contended, sapped productivity and dynamism.

Watanabe’s research shows that since January 2022, prices have been less sticky and more dispersed. Coincidentally, the Nikkei’s latest rally began a year later.

This in great part reflects the enthusiasm of foreign investors such as Warren Buffett , shareholder-friendly changes in corporate governance, and Japan’s importance as an alternative to China for high-end manufacturing and technology.

Inflation, though, might also be a factor, said Paul Sheard , a former vice chairman at S&P Global who has studied the Japanese economy for decades. He added that investors care about nominal, not real, stock prices, earnings, dividends and cash flow.

Higher inflation flatters all those metrics. That benefit might be neutralised by higher interest rates, but Japanese bond yields have risen less than expected inflation, so real yields are down to minus 0.6%.

So perhaps inflation is reviving businesses’ and investors’ animal spirits. Even so, growth last year was about the same as before the pandemic and turned slightly negative in the third and fourth quarters, producing a technical recession . What’s more, wages have lagged behind inflation, and Prime Minister Fumio Kishida ’s approval ratings have plummeted.

Japan might have prevailed in its war against deflation. But ordinary Japanese have yet to see a peace dividend.

A sharp technology sell-off has exposed a new anxiety on global markets: whether the enormous borrowing behind the artificial-intelligence infrastructure boom can generate sufficient returns as interest rates rise and Chinese competition intensifies.

The artificial-intelligence investment boom has powered technology shares, semiconductor manufacturers and data-centre operators to extraordinary heights. Last week, investors were given a reminder that much of this expansion is being built with borrowed money.

The technology-heavy Nasdaq Composite fell 4.5 per cent over the week ended October 16, its weakest performance since late June. Semiconductor shares suffered an even deeper correction, with the Philadelphia Semiconductor Index losing about 11.4 per cent.

The selling spread quickly through global markets. Micron Technology fell 14.6 per cent over the week, while South Korea’s Samsung Electronics and SK Hynix dropped approximately 18 per cent and 24 per cent respectively.

This was more than a routine bout of profit-taking. Investors were reassessing three interconnected risks: higher interest rates, the rapidly expanding debt burden attached to AI infrastructure and the prospect of stronger competition from Chinese memory-chip manufacturers.

The debt behind the AI build-out

Artificial intelligence requires a physical infrastructure network of enormous scale. Data centres must be built, advanced processors purchased, power supplies secured and cooling systems installed before customers begin generating meaningful revenue from them.

Technology companies are increasingly supplementing their own cash with corporate bonds, syndicated loans, equipment leases, private credit and project-level financing.

JPMorgan describes the emerging funding model as a combination of conventional corporate borrowing and project finance tied to individual data-centre assets. In Australia, the Reserve Bank estimates that syndicated loans accounted for approximately three-quarters of data-centre financing during 2025 and 2026 to date.

The numbers are becoming large enough to affect broader credit markets. The Federal Reserve Bank of Dallas has cited Wall Street estimates suggesting AI-related investment-grade bond issuance could approach US$300 billion in 2026 alone.

That borrowing is not automatically problematic. Debt can be an efficient way to finance long-lived infrastructure when future revenue is sufficiently predictable. The concern is that AI technology, customer demand and computing economics are changing much faster than the repayment schedules attached to the assets.

A data centre financed today may carry debt for years. Investors must therefore make assumptions about future utilisation rates, electricity prices, chip performance, customer concentration and the amount businesses will ultimately pay for AI computing.

When interest rates rise, those assumptions become less forgiving.

Inflation changes the calculation

September’s US inflation data intensified the pressure. Consumer prices increased 3.7 per cent over the year, ahead of market expectations and up from 3.4 per cent in August.

The hotter reading reduced confidence that interest rates would fall quickly and pushed bond yields higher. That matters particularly for companies whose valuations depend on profits expected well into the future, as well as highly leveraged infrastructure operators that may need to refinance.

CoreWeave has emerged as a closely watched test case. The specialist cloud-computing company has accumulated substantial debt and lease obligations to build AI capacity, while relying on a concentrated group of large technology customers.

Its shares fell sharply during the sell-off, while the cost of insuring its debt against default climbed. CoreWeave has argued that its contracted backlog more than covers its obligations and that financial markets do not always understand its business model. Nevertheless, its securities have become a proxy for investor confidence in debt-funded AI infrastructure.

Oracle, another major investor in AI computing capacity, fell 8.8 per cent in Friday trading, while CoreWeave dropped 15.5 per cent.

The question is shifting from how much AI infrastructure can be built to how profitably it can be operated.

China adds another source of pressure

Interest rates were not the only catalyst. Reports of advances by Chinese memory-chip producer ChangXin Memory Technologies raised concerns that lower-cost Chinese products could increase competition across the global semiconductor industry.

Memory chips are essential to AI systems, but the industry is historically cyclical. Periods of tight supply and high pricing can encourage rapid investment, eventually producing oversupply and falling margins.

The prospect of a well-funded Chinese competitor expanding its technological capabilities unsettled investors in Samsung, SK Hynix and Micron. It also demonstrated that AI-related demand does not insulate chipmakers from conventional competitive pressures.

That combination—slower rate cuts, more expensive financing and potentially cheaper supply—challenged the assumption that every company exposed to AI would enjoy continually expanding margins.

A reset rather than the end of the boom

The sell-off does not establish that the AI boom is ending. Demand for computing power remains strong, the largest technology companies continue to generate formidable cash flows and many infrastructure projects are backed by long-term customer contracts.

What has changed is the market’s willingness to overlook the price and financing structure of that growth.

The most resilient companies are likely to be those able to fund investment from operating cash flow, secure long-duration customers and demonstrate that new capacity will earn returns comfortably above its financing costs.

More speculative operators may face greater scrutiny, particularly where debt is expensive, customers are concentrated or expected revenue depends on demand that has not yet materialised.

For Australian investors, the lesson extends beyond US technology shares. Local data-centre operators, infrastructure funds, electricity suppliers and property groups are increasingly exposed to the same investment cycle.

Artificial intelligence may remain one of the defining growth themes of the decade. But last week’s correction showed that enthusiasm for the technology does not eliminate financial discipline.

The next stage of the AI boom will be judged not only by computing power, model performance or demand for chips, but by something more traditional: whether the assets being financed can generate enough cash to repay the money borrowed to build them.

Fact box

Nasdaq Composite: Down 4.5 per cent for the week ended October 16, 2026

Philadelphia Semiconductor Index: Down approximately 11.4 per cent

Micron Technology: Down approximately 14.6 per cent

Samsung Electronics: Down approximately 18 per cent

SK Hynix: Down approximately 24 per cent

US September inflation: 3.7 per cent annually

Estimated 2026 AI-related investment-grade issuance: Approximately US$300 billion