Japan's CPI, published monthly by the Ministry of Internal Affairs and Communications (MIC) Statistics Bureau, measures changes in the prices of a comprehensive basket of consumer goods and services. After nearly three decades where inflation was absent or negative, Japan has experienced a historic return of sustained price increases since 2022.

Why It Matters

Japan's CPI trajectory is arguably the single most consequential macroeconomic variable for global fixed income markets. It determines whether the BOJ can sustain its exit from the world's most extreme monetary experiment — negative interest rates, yield curve control, and massive asset purchases that made the BOJ the largest holder of Japanese Government Bonds and a top-10 holder of Japanese equities via ETFs.

Japan's Inflation History: A Unique Case

Basket Composition

Japan's CPI basket weights (updated every 5 years, last in 2020):

Notably, medical care costs are partially regulated by the government (national health insurance), dampening healthcare inflation.

Three Measures the BOJ Watches

The Wage-Price Spiral Question

The critical question is whether Japan has finally achieved a self-sustaining "wage-price spiral" — where tight labor markets drive wages higher, companies pass costs to consumers, and consumers accept higher prices. Evidence from the 2024 Shunto spring wage negotiations (~5.3% average increase, highest in 33 years) suggests this cycle may be establishing itself.

Market Impact

Rising CPI strengthens BOJ rate hike expectations, which:

Falling CPI reignites deflation fears, weakens the yen, and forces the BOJ to pause or reverse normalization — reviving the "Japanification" narrative that haunted global policy discussions for years.