IESET.
Hypotheses·growth·demo_japan_refusal_immigration_counterfactual

Japan's de facto policy of refusing large-scale immigration through the 1990s-2010s, in combination with its rapid ageing, produced a working-age population contraction larger than any major OECD comparator.

The hypothesis estimates a counterfactual: under comparator-OECD-average net migration rates, what would Japan's working-age share and per-capita growth have been? The hypothesis predicts the realised gap is substantial: realised working-age share is at least 4pp below the migration-equalised counterfactual by 2020.

PARTIALengine/runs/demo_japan_refusal_immigration_counterfactual

PARTIAL — shape=panel_summary, sign opposite claim + but magnitude tiny; |Δ_log|=0.0834, ratio=0.92

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

policy briefMixed or noisy

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

The evidence is suggestive but not decisive. shape=panel_summary, sign opposite claim + but magnitude tiny; |Δ_log|=0.0834, ratio=0.92

why it matters

Growth claims can look convincing in single success stories. This test asks whether the pattern survives a broader comparison.

how the test works

It compares 10 country or place units from 1990 to 2023, using a descriptive design.

what was measured
What changed
  • Net migration rate
What we checked
  • Working age population share
  • Real income per capita growth
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/demo_japan_refusal_immigration_counterfactual
1007550250199020072023JPNDEUITAKORUSAGBRFRA
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show working_age_population_share across 10 sampled countries over 1990–2023.
The shapes above are stylised — none of the lines are real data.
Placeholder for demo_japan_refusal_immigration_counterfactual. Published chart will be generated from engine/runs/demo_japan_refusal_immigration_counterfactual/chart_data.json.

Pre-registration

pre-registered
first-spec commit 098ce96 · 2026-04-30T12:57:33Z
run generated · 2026-04-30T08:07:38Z

Japan's de facto policy of refusing large-scale immigration through the 1990s-2010s, in combination with its rapid ageing, produced a working-age population contraction larger than any major OECD comparator. The hypothesis estimates a counterfactual: under comparator-OECD-average net migration rates, what would Japan's working-age share and per-capita growth have been? The hypothesis predicts the realised gap is substantial: realised working-age share is at least 4pp below the migration-equalised counterfactual by 2020.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if realised JPN working-age share is at least 4pp below the migration-equalised counterfactual by 2020, AND implied per-capita growth gap is at least 0.3pp annualised over 1990-2023. REFUTED if working-age gap < 2pp or growth gap insignificant.

formal test & threshold
test:      descriptive_japan_migration_counterfactual
threshold: wap_gap_2020 >= 4.0 AND implied_growth_gap >= 0.3

Method

Template
descriptive
Sample
10 countries · 1990 – 2023
Evidence type
descriptive

Counterfactual simulation: replace Japan's net-migration-rate with the comparator-OECD average and propagate through population dynamics; report gap between realised and counterfactual working-age share by 2020 and implied per-capita growth.

Data

VariableSourceTransform
working_age_population_share
outcome
world_bank_wdi:SP.POP.1564.TO.ZStier 2
level
real_gdp_per_capita_growth
outcome
world_bank_wdi:NY.GDP.PCAP.KD.ZGtier 2
level
net_migration_rate
treatment
world_bank_wdi:SM.POP.NETMtier 2
level
total_fertility_rate
control
world_bank_wdi:SP.DYN.TFRT.INtier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — demo_japan_refusal_immigration_counterfactual

Verdict: PARTIAL — shape=panel_summary, sign opposite claim + but magnitude tiny; |Δ_log|=0.0834, ratio=0.92

Pre-registration

  • Claim: Japan's de facto policy of refusing large-scale immigration through the 1990s-2010s, in combination with its rapid ageing, produced a working-age population contraction larger than any major OECD comparator. The hypothesis estimates a counterfactual: under comparator-OECD-average net migration rates, what would Japan's working-age share and per-capita growth have been? The hypothesis predicts the realised gap is substantial: realised working-age share is at least 4pp below the migration-equalised counterfactual by 2020.
  • Falsification rule: SUPPORTED if realised JPN working-age share is at least 4pp below the migration-equalised counterfactual by 2020, AND implied per-capita growth gap is at least 0.3pp annualised over 1990-2023. REFUTED if working-age gap < 2pp or growth gap insignificant.
  • Falsification test: descriptive_japan_migration_counterfactual

Comparison

  • shape: panel_summary
  • treatment_country: JPN
  • treatment_value: 58.867783865753786
  • donor_pool_median: 63.98787283510543
  • ratio: 0.9199834477613291
  • log_diff: -0.08339960066467356
  • n_donor_countries: 9
  • end_year_window: [2018, 2023]

Extracted threshold: {'pp': 4.0}

Variables resolved

  • world_bank_wdi:SP.POP.1564.TO.ZS → working_age_population_share (outcome, publisher=world_bank_wdi, n=17030)
  • world_bank_wdi:NY.GDP.PCAP.KD.ZG → real_gdp_per_capita_growth (outcome, publisher=world_bank_wdi, n=13961)
  • world_bank_wdi:SM.POP.NETM → net_migration_rate (treatment, publisher=world_bank_wdi, n=17292)
  • world_bank_wdi:SP.DYN.TFRT.IN → total_fertility_rate (controls, publisher=world_bank_wdi, n=16998)

Generated by scripts/run_descriptive.py at 2026-04-30T08:07:38+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.