thesisPrototype

Government data

Tokyo CPI All Items YoY, Sep 2026 Prelim

What will the Statistics Bureau of Japan first print for the 2026-09 Ku-area of Tokyo mid-month preliminary Consumer Price Index, all items, year-over-year percent change, not seasonally adjusted?

Overdue · was due Oct 2, 2026

The resolver has no route for this target's reference. The target was registered with a generic source link rather than a resolver binding.

registration: series statjp.cpi.tokyo_all_items_yoy

NO_ROUTE_GENERIC_URL · resolver status as of Oct 7, 2026

Forecast

2.1%
1.7%–2.5%
80% prediction interval
gpt-5.5Run record ↗
1.11.72.32.92025-092026-08Oct 20262.1%
historyforecast path80% interval
Probability distribution

Cumulative probability

Chance that the outcome is at or below each value.

0%25%50%75%100%1.1%2.1%3.1%Forecast value

Shaded band: 80% interval (1.7%–2.5%). Dashed line: point estimate (2.1%).

Derived from the point estimate and 80% interval; the agent did not report a full distribution.

Analysis

§Tokyo all-items CPI preliminary forecast for September 2026

The resolver is the Ku-area of Tokyo mid-month preliminary, all-items CPI, not seasonally adjusted, year-over-year percent change. The registered target contract specifies the 2020-base Tokyo ku-area preliminary CPI e-Stat table 1-2 workbook, field/series code 0001, first print; this forecast keeps that resolver rather than the later final Tokyo value or national CPI.

▸ Reported tool use: official.lookupmodel report
Checked Statistics Bureau of Japan CPI release schedule for the Ku-area of Tokyo preliminary survey month September 2026.
↳ The official schedule lists survey month September for Ku-area of Tokyo preliminary with release date October 2, 2026, inside the registered 2026-09-30 to 2026-10-08 expectedReleaseWindow; the same schedule lists August release on August 28, 2026 and October survey release on October 30, 2026.
▸ Reported tool use: official.lookupmodel report
Read the current Statistics Bureau Tokyo preliminary PDF for table 1 headline all-items values.
↳ The August 2026 preliminary all-items index was 102.4 and the all-items year-over-year change was 1.9 percent; July 2026 was index 102.0 and 1.8 percent year-over-year; June 2026 was index 101.5 and 1.6 percent year-over-year.
▸ Reported tool use: official.lookupmodel report
Read the official table 1 recent all-items YoY sequence in the August 2026 Tokyo preliminary PDF.
↳ Fetched all-items YoY prints were 2025-09 2.5, 2025-10 2.7, 2025-11 2.7, 2025-12 2.0, 2026-01 1.6, 2026-02 1.6, 2026-03 1.5, 2026-04 1.4, 2026-05 1.3, 2026-06 1.6, 2026-07 1.8, and 2026-08 1.9 percent.
▸ Reported tool use: official.lookupmodel report
Read the same official PDF for level, momentum, and component information around the latest print.
↳ Official all-items indexes were 2025-08 100.4, 2025-09 99.8, 2026-07 102.0, and 2026-08 102.4; seasonally adjusted all-items monthly changes were 2026-06 0.3, 2026-07 0.4, and 2026-08 0.2 percent; August energy YoY was -0.7 with contribution -0.03 and food excluding fresh food YoY was 3.8 with contribution 0.87.

Reference class/base rate: for this same official Tokyo preliminary all-items YoY series, the recent 12-print history from 2025-09 through 2026-08 averages about 1.88 percent, with the last three prints at 1.6, 1.8, and 1.9 percent. This is a persistence/recent-delta prior, not a fitted formal model, and it supports a near-2 percent prior before month-specific adjustment.

Prior/update/interval: persistence prior is August 2026 all-items YoY = 1.9 using the official 2025-09 to 2026-08 same-variant history. Adjustment components: level/base effect adds about +0.2 because September 2025 all-items index 99.8 was 0.6 below August 2025's 100.4, while 2026 momentum is positive but likely partly offset by normal September seasonal softness; energy drag roughly -0.1 and sticky food/rent services roughly +0.1, net point = 2.1. Interval method: month-to-month changes in YoY prints from the 2025-09 through 2026-08 official same-variant sample are +0.2, 0.0, -0.7, -0.4, 0.0, -0.1, -0.1, -0.1, +0.3, +0.2, +0.1, so sigma = 0.27 percentage point; 1.28*sigma = 0.35, rounded to an 80 percent interval of 1.7 to 2.5 percent.

Upside risk is a smaller-than-usual September unadjusted decline, renewed food price pressure, or less energy drag, which would land above the interval. Downside risk is a sharper September seasonal fall, weaker fresh food, or stronger utility/gasoline subsidy drag; a broad monthly index drop of about 0.8 percent from August would land outside the interval on the low side.

Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

Key drivers

  • August all-items YoY was 1.9 percent and still rising modestly
  • September 2025 index base was low after a -0.6 percent monthly fall
  • Recent seasonally adjusted all-items momentum was positive at 0.2 to 0.4 percent per month
  • Energy was a drag in August while food and rent remained positive contributors

Tool evidence

This run has no captured tool responses. “Reported tool use” in the analysis is the model’s account, not an archived tool response.

Sources and resolution

Official source
Statistics Bureau of Japan CPI Tokyo preliminary release
Resolution date
October 2, 2026· outcome not recorded
Resolution rule
Resolve to the first official Statistics Bureau of Japan print for the 2026-09 2020-base CPI Ku-area of Tokyo mid-month preliminary all-items series in the release's e-Stat table 1-2 workbook, field/series code 0001, year-over-year percent change in percent computed from the rounded index and rounded to one decimal place. Use the first print only; ignore later revisions or final values.
Run details

The analysis is the model’s written report. Tool-use descriptions in that report are model claims; the activity artifacts contain the execution record.

thesis.analyst · gpt-5.5 · fast · v2.5.11

pre-submit review · completed

Draft is mostly coherent, but the resolver text conflicts with the registered target contract on CPI base/table identity.

  • blocking resolver: The registered sourceBinding specifies the 2020-base Tokyo ku-area preliminary CPI table, while the draft resolutionRule says 2025-base CPI.
  • info optional_suggestion: State explicitly that the October 2, 2026 resolutionDate comes from the official release schedule and falls inside the registered September 30 to October 8 expectedReleaseWindow.
  • info optional_suggestion: Add one sentence saying the time-series prior is a persistence/recent-delta prior rather than a fitted formal model, to satisfy stricter model-prior checks.
  • info optional_suggestion: The interval method is acceptable, but clarify that sigma is based on month-to-month changes in YoY prints from the 2025-09 through 2026-08 official same-variant sample.

disposition accepted: Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

disposition not applicable: Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

disposition not applicable: Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

disposition not applicable: Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

Activity artifacts

Complete original trace

§Tokyo all-items CPI preliminary forecast for September 2026

The resolver is the Ku-area of Tokyo mid-month preliminary, all-items CPI, not seasonally adjusted, year-over-year percent change. The registered target contract specifies the 2020-base Tokyo ku-area preliminary CPI e-Stat table 1-2 workbook, field/series code 0001, first print; this forecast keeps that resolver rather than the later final Tokyo value or national CPI.

▸ Reported tool use: official.lookupmodel report
Checked Statistics Bureau of Japan CPI release schedule for the Ku-area of Tokyo preliminary survey month September 2026.
↳ The official schedule lists survey month September for Ku-area of Tokyo preliminary with release date October 2, 2026, inside the registered 2026-09-30 to 2026-10-08 expectedReleaseWindow; the same schedule lists August release on August 28, 2026 and October survey release on October 30, 2026.
▸ Reported tool use: official.lookupmodel report
Read the current Statistics Bureau Tokyo preliminary PDF for table 1 headline all-items values.
↳ The August 2026 preliminary all-items index was 102.4 and the all-items year-over-year change was 1.9 percent; July 2026 was index 102.0 and 1.8 percent year-over-year; June 2026 was index 101.5 and 1.6 percent year-over-year.
▸ Reported tool use: official.lookupmodel report
Read the official table 1 recent all-items YoY sequence in the August 2026 Tokyo preliminary PDF.
↳ Fetched all-items YoY prints were 2025-09 2.5, 2025-10 2.7, 2025-11 2.7, 2025-12 2.0, 2026-01 1.6, 2026-02 1.6, 2026-03 1.5, 2026-04 1.4, 2026-05 1.3, 2026-06 1.6, 2026-07 1.8, and 2026-08 1.9 percent.
▸ Reported tool use: official.lookupmodel report
Read the same official PDF for level, momentum, and component information around the latest print.
↳ Official all-items indexes were 2025-08 100.4, 2025-09 99.8, 2026-07 102.0, and 2026-08 102.4; seasonally adjusted all-items monthly changes were 2026-06 0.3, 2026-07 0.4, and 2026-08 0.2 percent; August energy YoY was -0.7 with contribution -0.03 and food excluding fresh food YoY was 3.8 with contribution 0.87.

Reference class/base rate: for this same official Tokyo preliminary all-items YoY series, the recent 12-print history from 2025-09 through 2026-08 averages about 1.88 percent, with the last three prints at 1.6, 1.8, and 1.9 percent. This is a persistence/recent-delta prior, not a fitted formal model, and it supports a near-2 percent prior before month-specific adjustment.

Prior/update/interval: persistence prior is August 2026 all-items YoY = 1.9 using the official 2025-09 to 2026-08 same-variant history. Adjustment components: level/base effect adds about +0.2 because September 2025 all-items index 99.8 was 0.6 below August 2025's 100.4, while 2026 momentum is positive but likely partly offset by normal September seasonal softness; energy drag roughly -0.1 and sticky food/rent services roughly +0.1, net point = 2.1. Interval method: month-to-month changes in YoY prints from the 2025-09 through 2026-08 official same-variant sample are +0.2, 0.0, -0.7, -0.4, 0.0, -0.1, -0.1, -0.1, +0.3, +0.2, +0.1, so sigma = 0.27 percentage point; 1.28*sigma = 0.35, rounded to an 80 percent interval of 1.7 to 2.5 percent.

Upside risk is a smaller-than-usual September unadjusted decline, renewed food price pressure, or less energy drag, which would land above the interval. Downside risk is a sharper September seasonal fall, weaker fresh food, or stronger utility/gasoline subsidy drag; a broad monthly index drop of about 0.8 percent from August would land outside the interval on the low side.

Review disposition: accepted the blocking resolver correction by changing the rule to the registered 2020-base Tokyo preliminary e-Stat table 1-2 workbook, field 0001, YoY-from-rounded-index target; accepted optional clarifications on the official October 2, 2026 schedule date, persistence/recent-delta prior, and sigma basis.

calibrated forecast · 80% CI
2.1%[1.7% · 2.5%]
Target metadata

Data point: statjp.cpi.tokyo_all_items_annual_rate.september_2026.preliminary

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