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Hypotheses·welfare architecture·welfare_pension_japan_2004_reform_sustainability

Japan's 2004 basic-pension reform (introducing macroeconomic-slide indexation, raising employee contributions in stages to 18.3% by 2017, raising age of full-eligibility to 65) materially extended fiscal sustainability of the pension system through the 2010s without producing the projected step-down in elderly-poverty rate, illustrating a sustainability-versus-adequacy tradeoff that motivated subsequent 2012 and 2020 supplementary-benefit additions.

PARTIALengine/runs/welfare_pension_japan_2004_reform_sustainability

PARTIAL — shape=pre_post, |Δ_log|=0.919; threshold 18.3%, observed 91.9%; claim direction ambiguous

confidence cueThe result is useful, but not decisive. Treat it as a clue, not a settled conclusion.

policy briefMixed or noisy

In ordinary language

In plain terms, this asks whether the policy story survives a real-world data check from 1995 to 2022.

plain answer

The evidence is suggestive but not decisive. shape=pre_post, |Δ_log|=0.919; threshold 18.3%, observed 91.9%; claim direction ambiguous

why it matters

This matters because welfare architecture claims should change belief only when they survive a pre-declared empirical test.

how the test works

It compares 1 country or place units from 1995 to 2022, using a descriptive design, with fixed effects for year.

what was measured
What we checked
  • Pension system balance per income
  • Elderly poverty rate
  • Pension replacement rate median
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/welfare_pension_japan_2004_reform_sustainability
1007550250199520092022JPN
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show pension_system_balance_per_gdp across 1 sampled countries over 1995–2022.
The shapes above are stylised — none of the lines are real data.
Placeholder for welfare_pension_japan_2004_reform_sustainability. Published chart will be generated from engine/runs/welfare_pension_japan_2004_reform_sustainability/chart_data.json.

Pre-registration

pre-registered
first-spec commit 098ce96 · 2026-04-30T12:57:33Z
run generated · 2026-04-30T08:07:40Z

Japan's 2004 basic-pension reform (introducing macroeconomic-slide indexation, raising employee contributions in stages to 18.3% by 2017, raising age of full-eligibility to 65) materially extended fiscal sustainability of the pension system through the 2010s without producing the projected step-down in elderly-poverty rate, illustrating a sustainability-versus-adequacy tradeoff that motivated subsequent 2012 and 2020 supplementary-benefit additions.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

Refuted if elderly-poverty rate falls more than 3pp by 2018, OR if pension-replacement rate rises after 2004, OR if pension-system balance fails to improve relative to pre-reform projection by at least 2% of GDP by 2015.

formal test & threshold
test:      descriptive_structural_break_pension_outcomes_2004
threshold: delta_elderly_poverty <= -3pp NOT met AND delta_replacement_rate <= 0 AND delta_balance_vs_projection >= +2pct of GDP

Method

Template
descriptive
Fixed effects
year
Clustering
country
Sample
1 countries · 1995 – 2022
Evidence type
descriptive

Descriptive time-series for JPN with structural-break test at 2004. Compare actual pension-balance trajectory and elderly-poverty path against pre-reform projections published in 2003 by MHLW.

Data

VariableSourceTransform
pension_system_balance_per_gdp
outcome
imf:GGXWDG_NGDPtier 2
level
elderly_poverty_rate
outcome
oecd:DSD_IDDtier 2
level_pct
pension_replacement_rate_median
outcome
oecd:DSD_PENSIONStier 2
level_pct
dependency_ratio
control
world_bank_wdi:SP.POP.DPND.OLtier 2
level
gdp_per_capita_real
control
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — welfare_pension_japan_2004_reform_sustainability

Verdict: PARTIAL — shape=pre_post, |Δ_log|=0.919; threshold 18.3%, observed 91.9%; claim direction ambiguous

Pre-registration

  • Claim: Japan's 2004 basic-pension reform (introducing macroeconomic-slide indexation, raising employee contributions in stages to 18.3% by 2017, raising age of full-eligibility to 65) materially extended fiscal sustainability of the pension system through the 2010s without producing the projected step-down in elderly-poverty rate, illustrating a sustainability-versus-adequacy tradeoff that motivated subsequent 2012 and 2020 supplementary-benefit additions.
  • Falsification rule: Refuted if elderly-poverty rate falls more than 3pp by 2018, OR if pension-replacement rate rises after 2004, OR if pension-system balance fails to improve relative to pre-reform projection by at least 2% of GDP by 2015.
  • Falsification test: descriptive_structural_break_pension_outcomes_2004

Comparison

  • shape: pre_post
  • country: JPN
  • cut_year: 2004
  • pre_mean: 77.22916666666667
  • post_mean: 193.67142857142855
  • delta: 116.44226190476188
  • log_delta: 0.9193858637871886
  • n_pre: 24
  • n_post: 28

Extracted threshold: {'percent': 18.3}

Variables resolved

  • imf:GGXWDG_NGDP → pension_system_balance_per_gdp (outcome, publisher=imf, n=8113)
  • world_bank_wdi:SP.POP.DPND.OL → dependency_ratio (controls, publisher=world_bank_wdi, n=17000)
  • world_bank_wdi:NY.GDP.PCAP.KD → gdp_per_capita_real (controls, publisher=world_bank_wdi, n=14131)

Variables missing data

  • oecd:DSD_IDD@DF_IDD (outcome, name=elderly_poverty_rate)
  • oecd:DSD_PENSIONS@DF_PENSIONS_REPL_RATE (outcome, name=pension_replacement_rate_median)

Generated by scripts/run_descriptive.py at 2026-04-30T08:07:40+00:00

Strongest opposing argument

Every hypothesis ships with its charitable opposing argument. The framework earns credibility by handling objections at their strongest, not weakest.

Authored framework. Read the transparency note.