IESET.
Hypotheses·distribution·tax_inequality_japan_consumption_tax_hikes

Japan's three consumption-tax hikes (1997 3->5, 2014 5->8, 2019 8->10 percent) raised the disposable-income Gini coefficient by at least 0.3 Gini-points cumulatively relative to G7-ex-JPN comparator synthetic control, with the regressivity bite partially offset by simultaneous tax-rebate / cash-transfer programmes.

The discriminating test is the cumulative disposable-Gini gap vs synth control over 1996-2020.

INCONCLUSIVEengine/runs/tax_inequality_japan_consumption_tax_hikes

INCONCLUSIVE_DATA_PENDING — insufficient pre-period coverage (years=0, donors=3)

confidence cueResult card produced; verdict unclassified.

policy briefCoverage too thin

In ordinary language

Over a long period, do more market-oriented institutions translate into higher income or productivity, once the comparison looks beyond a single success story?

plain answer

This test cannot make a firm call yet. insufficient pre-period coverage (years=0, donors=3)

why it matters

Distributional claims often sound morally clear but are empirically complex. This test asks whether the proposed channel explains real differences across places.

how the test works

It compares 7 country or place units from 1990 to 2022, using a synthetic control design, with fixed effects for country and year.

what was measured
What changed
  • Jpn consumption tax hike 1997
  • Jpn consumption tax hike 2014
What we checked
  • Inequality disposable income
  • Top 10pct pretax income share
what this does not prove

A single test is not the whole truth. It narrows the claim under a specific sample, time period, and method. Strong policy conclusions need the pattern to survive nearby tests, alternative data, and serious objections.

verification

No evidence packet has been generated yet.

Results

engine/runs/tax_inequality_japan_consumption_tax_hikes
1007550250199020062022JPNUSAGBRFRADEUITACAN
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show gini_disposable_income across 7 sampled countries over 1990–2022.
The shapes above are stylised — none of the lines are real data.
Placeholder for tax_inequality_japan_consumption_tax_hikes. Published chart will be generated from engine/runs/tax_inequality_japan_consumption_tax_hikes/chart_data.json.

Pre-registration

registration ordering unverified
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z
run generated · 2026-05-04T12:34:35Z
Run timestamp predates this path's first git-add commit (rebase, rename, or pre-git local run). Spec hash is still the path's first-add commit — not repository HEAD — but ordering is not a clean pre-registration proof.

Japan's three consumption-tax hikes (1997 3->5, 2014 5->8, 2019 8->10 percent) raised the disposable-income Gini coefficient by at least 0.3 Gini-points cumulatively relative to G7-ex-JPN comparator synthetic control, with the regressivity bite partially offset by simultaneous tax-rebate / cash-transfer programmes. The discriminating test is the cumulative disposable-Gini gap vs synth control over 1996-2020.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if Japanese disposable Gini cumulative deviation from G7- ex-JPN synthetic over 1996-2020 exceeds +0.3 Gini-points at p<0.10. REFUTED if cumulative deviation is below +0.1 Gini-point or negative at p<0.10.

formal test & threshold
test:      Synthetic-control with G7-ex-JPN donor pool, treated JPN 1997.

Method

Template
synthetic_control
Fixed effects
country, year
Clustering
country
Sample
7 countries · 1990 – 2022
Evidence type
associational

Synthetic-control with G7-ex-JPN donor pool. Multi-treatment extension via Callaway-Sant'Anna staggered DiD as robustness.

Data

VariableSourceTransform
gini_disposable_income
outcome
world_bank_wdi:SI.POV.GINItier 2
level
top_10pct_pretax_income_share
outcome
owid:top-10-share-of-total-incometier 2
level
jpn_consumption_tax_hike_1997
treatment
constructed:indicator = 1 for JPN, year >= 1997tier 5
indicator
jpn_consumption_tax_hike_2014
treatment
constructed:indicator = 1 for JPN, year >= 2014tier 5
indicator
jpn_consumption_tax_hike_2019
treatment
constructed:indicator = 1 for JPN, year >= 2019tier 5
indicator
log_real_gdp_per_capita
control
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log
unemployment_rate
control
world_bank_wdi:SL.UEM.TOTL.ZStier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — tax_inequality_japan_consumption_tax_hikes

Verdict: INCONCLUSIVE_DATA_PENDING — insufficient pre-period coverage (years=0, donors=3)

Pre-registration

  • Claim: Japan's three consumption-tax hikes (1997 3->5, 2014 5->8, 2019 8->10 percent) raised the disposable-income Gini coefficient by at least 0.3 Gini-points cumulatively relative to G7-ex-JPN comparator synthetic control, with the regressivity bite partially offset by simultaneous tax-rebate / cash-transfer programmes. The discriminating test is the cumulative disposable-Gini gap vs synth control over 1996-2020.
  • Falsification rule: SUPPORTED if Japanese disposable Gini cumulative deviation from G7- ex-JPN synthetic over 1996-2020 exceeds +0.3 Gini-points at p<0.10. REFUTED if cumulative deviation is below +0.1 Gini-point or negative at p<0.10.

Synthetic-control estimate

  • Error: insufficient pre-period coverage (years=0, donors=3)

Variables resolved

  • world_bank_wdi:SI.POV.GINI → gini_disposable_income (outcome, n=2430)
  • owid:top-10-share-of-total-income → top_10pct_pretax_income_share (outcome, n=3294)
  • constructed: indicator = 1 for JPN, year >= 1997 → jpn_consumption_tax_hike_1997 (treatment, n=231)
  • constructed: indicator = 1 for JPN, year >= 2014 → jpn_consumption_tax_hike_2014 (treatment, n=231)
  • constructed: indicator = 1 for JPN, year >= 2019 → jpn_consumption_tax_hike_2019 (treatment, n=231)
  • world_bank_wdi:NY.GDP.PCAP.KD → log_real_gdp_per_capita (controls, n=14066)
  • world_bank_wdi:SL.UEM.TOTL.ZS → unemployment_rate (controls, n=8071)

Generated by scripts/run_synth_did.py at 2026-05-04T12:34:35+00:00

Notes

Tax-inequality candidate, swarm-S6 batch 4.

Authored framework. Read the transparency note.