When the Nikkei 225 peaked on the final trading day of 1989, Japanese executives toasted what seemed like permanent prosperity. Within three years, the index had lost half its value. Within a decade, property prices in Tokyo had fallen by roughly eighty percent from their highs. What followed was not a recession in the ordinary sense but something economists had to invent new vocabulary to describe: a prolonged, grinding stagnation that defied every conventional remedy.

The Japanese experience—often called the Lost Decade, though it arguably stretched into two—offers a masterclass in what can go wrong when asset bubbles inflate beyond reason and then implode. It also demonstrates how difficult recovery becomes once deflation takes hold of an economy's psychology.

The anatomy of a bubble

Japan's bubble was built on cheap money and speculative frenzy. After the 1985 Plaza Accord weakened the dollar against the yen, the Bank of Japan cut interest rates to stimulate domestic demand and offset the export headwinds. The liquidity had to go somewhere, and it went everywhere: into stocks, into real estate, into golf course memberships that traded for the price of apartments. At the peak, the grounds of Tokyo's Imperial Palace were said to be worth more than all the real estate in California—a statistic that may be apocryphal but captures the delirium accurately.

When the central bank finally raised rates to cool speculation, the bubble did not deflate gently. It ruptured. Banks found themselves holding loans collateralised by assets worth a fraction of their previous valuations. Rather than recognise losses and recapitalise, many institutions engaged in what became known as "evergreening"—rolling over bad loans to zombie companies that could never repay them, simply to avoid booking the write-downs.

Why deflation is so sticky

The deeper lesson of Japan's lost years concerns expectations. Once consumers and businesses come to believe that prices will fall, they behave accordingly: delaying purchases, hoarding cash, demanding higher real wages even as nominal wages stagnate. This creates a self-reinforcing cycle that monetary policy struggles to break. The Bank of Japan eventually pushed interest rates to zero—and later into negative territory—yet growth remained anaemic for years.

Fiscal stimulus, deployed repeatedly throughout the 1990s, produced roads and bridges but not sustained recovery. Critics argued the spending was misdirected; defenders countered that without it, the outcome would have been worse. What is clear is that neither tool worked quickly or cleanly. Japan's experience became a cautionary tale cited whenever central bankers elsewhere worried about the "zero lower bound" and the risk of falling into a liquidity trap.

The echoes elsewhere

Western policymakers studied Japan obsessively after the 2008 financial crisis. The Federal Reserve's aggressive quantitative easing, the European Central Bank's eventual embrace of bond-buying, the willingness to tolerate larger fiscal deficits—all were informed by Tokyo's painful experiment. The explicit goal was to avoid "turning Japanese," a phrase that entered the economic lexicon as shorthand for secular stagnation.

Yet the parallels are imperfect. Japan's demographics—an ageing, shrinking population—amplified its troubles in ways that do not map neatly onto other economies. And its cultural reluctance to allow corporate failures may have prolonged the zombie-company problem beyond what would occur in more ruthless capitalist systems.

Our take

Japan's lost decade is not a morality tale about reckless speculation, though speculation certainly played its part. It is a reminder that economies are governed as much by psychology as by policy levers, and that once confidence curdles into caution, restoring it can take a generation. Every finance minister staring at a housing bubble or a debt overhang should keep a copy of the Nikkei's 1989 chart on their desk—not as prophecy, but as possibility.