Verdict No.001 · Scored in public
Miss

The predicted entry controls on Japan's new FY2027 investment window were not imposed.

Prior probability
75%
Resolution deadline
31 Jul 2026, 23:59 JST
Verdict date
2 Aug 2026
Editorial Correction — 22 August 2026

Social posts published on 3 August 2026 misstated the proposition underlying Forecast No. 001.

The actual forecast concerned Japan's FY2027 budget-request guidelines and whether the new investment envelope would be subject to an entry-stage restriction. The social posts incorrectly described it as a forecast about domestic production investment in Japan's FY2026 Basic Policy.

The verdict remains MISS.

No forecast proposition, published confidence level, deadline, or verdict has been changed. This note corrects only the subsequent description of the forecast.

01 — Conclusion

Nihonbashi Forecast No.001 is scored as a Miss.

On 30 July 2026, the Japanese government approved the Basic Policy for FY2027 Budget Requests. The decision was made before the forecast deadline, so this is not a timing miss.

However, the newly established "Strong and Prosperous Japan" Investment Window did not contain either of the entry-stage controls specified in the preregistered forecast:

  1. A closed and limited list of eligible policy categories
  2. A requirement that submissions be limited to item-only requests without a specified amount

Instead, the government allowed ministries to request the necessary amounts without a request ceiling. Item-only requests were permitted as an option, but were not mandatory.

The mere appearance of the term "item-only request" is therefore not sufficient to score the forecast as a Hit. Under the preregistered resolution criteria, the correct verdict is Miss.

02 — The Preregistered Forecast

What was called, on 22 July 2026.

"Japan's FY2027 budget-request guidelines will impose entry-stage controls on the newly created strategic investment window, either through a limited list of eligible requirements or by restricting submissions to item-only requests without a specified amount."

A Hit required the Cabinet-approved document to state at least one of the following:

  • A closed and limited list of eligible requirements
  • Mandatory item-only requests without specified amounts

Original preregistration (Japanese) note.com/nb_forecast/n/n4d5b5721b80d

03 — What the Government Approved

The "Strong and Prosperous Japan" Investment Window.

The Cabinet-approved policy formally established the "Strong and Prosperous Japan" Investment Window.

It covers policies expected to raise Japan's potential growth rate, taking account of the Japan Growth Strategy, regional future strategies, and related policies. Multi-year plans are to be the basic format, while the relationship with ordinary expenditure will be examined during the budget-formulation process.

For submissions under the new window, however, the policy provides that:

  • No request ceiling will be imposed
  • Item-only requests may be used
  • Ministries may request the amounts considered necessary

Allowing item-only requests is fundamentally different from requiring all submissions to be item-only.

The first expands the available methods of submission. The second would prevent ministries from requesting specified amounts at the entry stage. The government adopted the first approach, not the second.

Official source (Cabinet decision, PDF) mof.go.jp/…/fy2027/sy260730a.pdf

FY2027 budget documents mof.go.jp/…/fy2027/index.html

04 — Resolution Table

How each preregistered condition scored.

Condition Actual outcome Result
Decision by 31 July 2026 30 July Met
Creation of the new investment window Formally established Met
Closed list of eligible requirements Open-ended wording including "and related policies" Not met
Mandatory item-only requests Optional; specified amounts may also be requested Not met
Request ceiling None Contrary to forecast
Final verdict MISS —
05 — Why the Forecast Missed

Right incentive, wrong location in the process.

The forecast placed substantial weight on the Ministry of Finance's institutional incentive to control spending at the request stage.

The Ministry's screening authority has not disappeared. Ordinary expenditure, policy priorities, subsidies, and funds will still be examined during the budget-formulation process.

But the mechanism adopted by the government was different from the one forecast.

The actual structure was:

  • No ceiling at the request stage
  • Ministries are encouraged to submit multi-year investment proposals
  • Fiscal control is exercised later, during budget screening

We forecast control at the entrance. The government instead opened the entrance and retained control at the screening stage.

The institutional incentive for fiscal control remained, but we misidentified where in the process it would be exercised.

06 — What the Forecast Did Capture

Correct observations that do not rescue the score.

The forecast was not wrong in every respect.

It correctly anticipated that:

  • A new investment window would appear in the budget-request guidelines
  • Multi-year planning would be central
  • The relationship with ordinary expenditure would be examined during budget formulation
  • Economically sensitive and strategically important sectors could receive separate treatment

These features show that the investment window is not a system of unrestricted spending.

They were not, however, the preregistered conditions for a Hit. Partially correct observations cannot be used to rescue the final score.

07 — Why This Is Not Lucky

The predicted mechanism did not occur at all.

Lucky was reserved for a case in which the predicted entry control was implemented, but for a different political or institutional reason from the one forecast.

Here, the predicted form of entry control was not implemented. The appropriate verdict is therefore Miss, not Lucky.

08 — Calibration

75% represented overconfidence in this case.

The forecast assigned a probability of 75%, but the predicted event did not occur.

The binary Brier Score is:

(0.75 − 0)² = 0.5625

One forecast is not enough to evaluate overall forecasting skill. It is enough, however, to show that 75% represented overconfidence in this case.

For future fiscal-policy forecasts, we will:

  • Separate "item-only requests are permitted" from "item-only requests are mandatory"
  • Forecast entry-stage controls and later budget screening separately
  • Analyse political intent and fiscal-institutional reactions as a sequence, not only as opposing forces
  • Define in advance that an open-ended list containing terms such as "and related policies" does not satisfy a limited-list condition
09 — Ledger Record

No.001 remains on the ledger — as a Miss.

No.001 · MISS

We correctly anticipated the timing, the creation of the investment window, and the continued role of budget screening.

We missed the most important element: the design of the request-stage mechanism.

Nihonbashi Forecast begins with a Miss.

The purpose of publishing forecasts is not merely to celebrate correct calls. It is to leave the location of each error on the map — and use it to make the next forecast slightly better.

Forecasts are registered in advance.

Verdicts are published.

Misses remain on the ledger.

Japanese audit record note.com/nb_forecast/n/n21241b8b8b89

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