thesisPrototype

Government data

Australia CPI annual rate, August 2026

What will the Australian Bureau of Statistics report as the FIRST PRINT August 2026 annual percentage change for CPI/3.10001.10.50.M: Consumer Price Index (CPI), percentage change from previous year, All groups CPI, Original, Australia, Monthly?

Forecast

3.8%
3.0%–4.6%
80% prediction interval
gpt-5.5Run record ↗

Cumulative probability

Chance that the outcome is at or below each value.

0%25%50%75%100%1.8%3.8%5.8%Forecast value

Shaded band: 80% interval (3.0%–4.6%). Dashed line: point estimate (3.8%).

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

Observed outcomeinside 80% interval
actual
4.0%
forecast
3.8% with 80% interval [3.0%, 4.6%]
error
+0.2% · absolute 0.2%
cdf score
CRPS 0.19 · PIT 0.60
source
abs Monthly Consumer Price Index (complete monthly CPI, dataflow CPI: annual change, all groups, original, weighted average of eight capital cities)

First print for 2026-08 captured from https://data.api.abs.gov.au/rest/data/CPI/3.10001.10.50.M?lastNObservations=30&format=jsondata on the official release date named by the cell's resolver.

Analysis

§Australia August 2026 CPI annual-rate forecast

Target identity is tied to the registered ledger slug australia-cpi-annual-rate-august-2026, unit percent, and dataPointId abs.cpi.all_groups.yoy.2026_08.first_print. The public specs.json check returned a 404 page during this run, so I used the local generated ledger target and target registration for slug identity rather than inventing a replacement.

▸ Reported tool use: abs.calendar.fetchmodel report
curl -sSL https://www.abs.gov.au/release-calendar/future-releases/202609 and extract Consumer Price Index entry
↳ ABS September 2026 future releases excerpt: Wednesday 30 September 2026 11:30am AEST Consumer Price Index, Australia; reference period August 2026. Numeric date used: 2026-09-30 and time 11:30am AEST.
▸ Reported tool use: abs.data_api.fetchmodel report
curl -sS https://data.api.abs.gov.au/rest/data/CPI/3.10001.10.50.M?lastNObservations=30&format=jsondata
↳ ABS CPI/3.10001.10.50.M returned observations: 2025-04=2.4, 2025-05=2.1, 2025-06=1.9, 2025-07=3.0, 2025-08=3.2, 2025-09=3.6, 2025-10=3.8, 2025-11=3.4, 2025-12=3.8, 2026-01=3.8, 2026-02=3.7, 2026-03=4.6, 2026-04=4.2, 2026-05=4.0, 2026-06=3.8.
▸ Reported tool use: abs.structure.fetchmodel report
read dimensions in same ABS JSON response for CPI/3.10001.10.50.M
↳ Same ABS response identifies MEASURE=3 Percentage change from previous year, INDEX=10001 All groups CPI, TSEST=10 Original, REGION=50 Australia, FREQ=M Monthly, unit=PCT Percent; latest numeric value is 2026-06=3.8.

Base rate/reference class: the 15 fetched monthly ABS annual-change prints from 2025-04 to 2026-06 have mean 3.42, sample std of values 0.772, range 1.9 to 4.6, and last print 3.8. The reference class is short because the registered complete monthly CPI API series only returned 15 observations.

▸ Reported tool use: model_candidates.localmodel report
compute benchmark candidates from fetched ABS values only
↳ thesis_model_candidate_v1 benchmarks: persistence point=3.8, p10=3.0, p50=3.8, p90=4.6, 80_interval=[3.0,4.6], 90_interval=[2.7,4.9], interval_method=two-step residual sigma from 14 successive changes, calibration_n=14, train_cutoff=2026-06, walk_forward_MAE=0.3571; mean-change candidate point=4.0, interval=[3.2,4.8], calibration_n=14, train_cutoff=2026-06, in-sample MAE proxy=0.3714.

Prior/update/interval: prior = last-print persistence from 2026-06 at 3.8 because its fetched walk-forward absolute-change proxy MAE 0.3571 is slightly better than the mean-change rule's 0.3714. Adjustment components: no direct August pre-release signal fetched, so update = 0.0 and point = 3.8. Successive changes are -0.3, -0.2, +1.1, +0.2, +0.4, +0.2, -0.4, +0.4, 0.0, -0.1, +0.9, -0.4, -0.2, -0.2; one-month sigma = 0.466, two-month sigma = sqrt(2)*0.466 = 0.659, and 80% half-width = 1.28*sigma = 1.28*0.659 = 0.844, rounded to 0.8. Implied bounds: 3.8 - 0.8 = 3.0 and 3.8 + 0.8 = 4.6.

Sanity check: with a 0.8-point half-width around persistence, 12 of the 14 one-step historical moves were inside the band; the two misses were +1.1 in 2025-07 and +0.9 in 2026-03. For a two-month August target this coverage check supports, but does not narrow, the interval.

Downside risk outside the interval: a faster disinflation sequence like another pair of -0.4 monthly changes would land below the interval. Upside risk outside the interval: a renewed price shock comparable to the +1.1 or +0.9 historical jumps would land above the interval.

Review disposition: accepted the optional ordering suggestion by placing the base-rate/reference-class step before the model-candidate comparison, and retained the interval calibration with an explicit note that the fetched sample is short. No required fixes were raised.

Key drivers

  • Last-print persistence at 3.8 percent
  • June-to-August two-step horizon
  • Recent pullback from March peak
  • No direct pre-release August signal fetched

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
Australian Bureau of Statistics, Consumer Price Index, Australia
Resolved
September 30, 2026
Resolution rule
Resolve from the ABS data API field CPI/3.10001.10.50.M, described in the registration as Monthly Consumer Price Index (complete monthly CPI, dataflow CPI: annual change, all groups, original, weighted average of eight capital cities). Use the first print for period 2026-08 only; later revisions do not count. Unit is percent and rounding is to one decimal place, matching ABS publication precision. The ABS September 2026 future-release calendar listed Consumer Price Index, Australia for reference period August 2026 on Wednesday 30 September 2026 at 11:30am AEST.
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 · full · v2.5.9

pre-submit review · completed

The draft is publication-ready against the rubric, with resolver identity, prior, update, interval, tails, and JSON fields internally coherent.

  • info optional_suggestion: Consider making the base-rate sentence appear immediately before the model-candidate comparison for stricter rubric ordering.
  • info optional_suggestion: The interval method is acceptable, but note that the calibration sample is very short if space allows.

disposition not applicable: Review disposition: accepted the optional ordering suggestion by placing the base-rate/reference-class step before the model-candidate comparison, and retained the interval calibration with an explicit note that the fetched sample is short. No required fixes were raised.

disposition not applicable: Review disposition: accepted the optional ordering suggestion by placing the base-rate/reference-class step before the model-candidate comparison, and retained the interval calibration with an explicit note that the fetched sample is short. No required fixes were raised.

Activity artifacts

Complete original trace

§Australia August 2026 CPI annual-rate forecast

Target identity is tied to the registered ledger slug australia-cpi-annual-rate-august-2026, unit percent, and dataPointId abs.cpi.all_groups.yoy.2026_08.first_print. The public specs.json check returned a 404 page during this run, so I used the local generated ledger target and target registration for slug identity rather than inventing a replacement.

▸ Reported tool use: abs.calendar.fetchmodel report
curl -sSL https://www.abs.gov.au/release-calendar/future-releases/202609 and extract Consumer Price Index entry
↳ ABS September 2026 future releases excerpt: Wednesday 30 September 2026 11:30am AEST Consumer Price Index, Australia; reference period August 2026. Numeric date used: 2026-09-30 and time 11:30am AEST.
▸ Reported tool use: abs.data_api.fetchmodel report
curl -sS https://data.api.abs.gov.au/rest/data/CPI/3.10001.10.50.M?lastNObservations=30&format=jsondata
↳ ABS CPI/3.10001.10.50.M returned observations: 2025-04=2.4, 2025-05=2.1, 2025-06=1.9, 2025-07=3.0, 2025-08=3.2, 2025-09=3.6, 2025-10=3.8, 2025-11=3.4, 2025-12=3.8, 2026-01=3.8, 2026-02=3.7, 2026-03=4.6, 2026-04=4.2, 2026-05=4.0, 2026-06=3.8.
▸ Reported tool use: abs.structure.fetchmodel report
read dimensions in same ABS JSON response for CPI/3.10001.10.50.M
↳ Same ABS response identifies MEASURE=3 Percentage change from previous year, INDEX=10001 All groups CPI, TSEST=10 Original, REGION=50 Australia, FREQ=M Monthly, unit=PCT Percent; latest numeric value is 2026-06=3.8.

Base rate/reference class: the 15 fetched monthly ABS annual-change prints from 2025-04 to 2026-06 have mean 3.42, sample std of values 0.772, range 1.9 to 4.6, and last print 3.8. The reference class is short because the registered complete monthly CPI API series only returned 15 observations.

▸ Reported tool use: model_candidates.localmodel report
compute benchmark candidates from fetched ABS values only
↳ thesis_model_candidate_v1 benchmarks: persistence point=3.8, p10=3.0, p50=3.8, p90=4.6, 80_interval=[3.0,4.6], 90_interval=[2.7,4.9], interval_method=two-step residual sigma from 14 successive changes, calibration_n=14, train_cutoff=2026-06, walk_forward_MAE=0.3571; mean-change candidate point=4.0, interval=[3.2,4.8], calibration_n=14, train_cutoff=2026-06, in-sample MAE proxy=0.3714.

Prior/update/interval: prior = last-print persistence from 2026-06 at 3.8 because its fetched walk-forward absolute-change proxy MAE 0.3571 is slightly better than the mean-change rule's 0.3714. Adjustment components: no direct August pre-release signal fetched, so update = 0.0 and point = 3.8. Successive changes are -0.3, -0.2, +1.1, +0.2, +0.4, +0.2, -0.4, +0.4, 0.0, -0.1, +0.9, -0.4, -0.2, -0.2; one-month sigma = 0.466, two-month sigma = sqrt(2)*0.466 = 0.659, and 80% half-width = 1.28*sigma = 1.28*0.659 = 0.844, rounded to 0.8. Implied bounds: 3.8 - 0.8 = 3.0 and 3.8 + 0.8 = 4.6.

Sanity check: with a 0.8-point half-width around persistence, 12 of the 14 one-step historical moves were inside the band; the two misses were +1.1 in 2025-07 and +0.9 in 2026-03. For a two-month August target this coverage check supports, but does not narrow, the interval.

Downside risk outside the interval: a faster disinflation sequence like another pair of -0.4 monthly changes would land below the interval. Upside risk outside the interval: a renewed price shock comparable to the +1.1 or +0.9 historical jumps would land above the interval.

Review disposition: accepted the optional ordering suggestion by placing the base-rate/reference-class step before the model-candidate comparison, and retained the interval calibration with an explicit note that the fetched sample is short. No required fixes were raised.

calibrated forecast · 80% CI
3.8%[3.0% · 4.6%]
Target metadata

Data point: abs.cpi.all_groups.yoy.2026_08.first_print

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