Tokyo core inflation hits 2.7%, fastest in 10 months, bolstering BOJ rate hike case

All three inflation measures in Tokyo exceeded expectations, with the Bank of Japan's preferred trend gauge coming in half a percentage point above forecasts. This outcome is expected to strengthen the case for an October rate increase and push short-term Japanese government bond yields higher, potentially supporting the yen against the dollar. For the BOJ, the broad nature of the price increases, particularly in services, carries more weight than the headline jump, given that water subsidies account for only part of the rise. Energy represents another factor: with Brent crude trading above $100 due to the Iran conflict and China halting fuel exports, higher imported fuel costs are likely to continue feeding into Japanese inflation when national data comes out later this month. A small uptick in unemployment is not expected to alter the policy discussion.

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Background

• Tokyo CPI preview: core inflation seen jumping to 2.4% as BOJ weighs its next hike

And the 'just the data' post from earlier:

• Japan September Tokyo CPI data surges ahead of expectations and August

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Tokyo inflation surged rather than simply rose in September, providing the BOJ with a compelling reason not to delay its next rate hike.

Summary:

• Tokyo core CPI (excluding fresh food) increased 2.7% year-on-year in September, compared with a 2.4% forecast and 1.8% in August
• Headline Tokyo CPI also climbed 2.7%, above the 2.5% projection and up from 1.9%
• CPI excluding fresh food and energy rose to 3.0% from 2.0%, versus a 2.5% estimate, the fastest since August 2025
• Services inflation accelerated to 2.3% from 1.4%; the phase-out of water subsidies played a role but gains were widespread
• Japan's August unemployment rate edged higher to 2.5% (expected 2.4%); the jobs-to-applicants ratio stayed at 1.18
• The BOJ publishes new quarterly forecasts at its October 29-30 meeting

Consumer inflation in Tokyo accelerated sharply in September, with core prices posting their fastest increase in 10 months and a key underlying inflation metric reaching 3%, strengthening the argument for further interest rate hikes by the Bank of Japan.

Core CPI in the capital, which strips out fresh food but includes fuel, rose 2.7% from a year earlier, climbing from 1.8% in August and easily beating the median estimate of 2.4%. This marked the first reading above the BOJ's 2% target since January and the fastest annual pace since November last year. Headline Tokyo CPI also increased 2.7%, exceeding expectations of 2.5% and rising from 1.9% in the prior month.

The measure that excludes both fresh food and energy, which the BOJ closely monitors as a gauge of trend inflation, jumped to 3.0% from 2.0%, surpassing forecasts of 2.5% and recording its fastest rise since August 2025.

Part of the acceleration came from the phasing out of water bill subsidies, but price increases were widespread, covering food, transport and hotel charges. Services inflation picked up to 2.3% from 1.4%, indicating that businesses are passing on higher labour costs amid a tight job market.

Separate data showed Japan's unemployment rate edged up to 2.5% in August, above the 2.4% forecast, while the jobs-to-applicants ratio remained at 1.18, in line with expectations.

The Tokyo figures are regarded as a leading indicator for national inflation and will feed into the BOJ's new quarterly price forecasts at its October 29-30 policy meeting. The central bank raised its policy rate to 1.25%, a 31-year high, in September, and Governor Kazuo Ueda has indicated a new phase focused on preventing inflation from exceeding its target.

Some economists expect core inflation to continue trending higher as energy costs from the Middle East conflict feed through to other prices, and they see the BOJ raising rates again by December. The strength of the September data is likely to intensify debate over whether the next move could come as early as the October meeting.