IESET.
Hypotheses·labour·demo_korea_fertility_cliff_2015_2024

South Korea experienced a "fertility cliff" 2015-2024 (TFR falling from ~1.24 to <0.8), globally unprecedented in peacetime.

The hypothesis predicts (a) Korea's TFR decline exceeds 3 standard deviations relative to OECD-comparator decadal changes, (b) the decline is concentrated in metropolitan/Seoul cohorts, and (c) early signals of working- age contraction are visible in 2020-2024 labour-market participation among 25-34 year olds.

PARTIALengine/runs/demo_korea_fertility_cliff_2015_2024

PARTIAL — shape=panel_summary, |Δ_log|=0.444, ratio=0.642; 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 2000 to 2024.

plain answer

The evidence is suggestive but not decisive. shape=panel_summary, |Δ_log|=0.444, ratio=0.642; claim direction ambiguous

why it matters

Labor-market rules often help some workers while risking job loss or slower hiring for others. This test looks for that tradeoff in observable employment or unemployment data.

how the test works

It compares 10 country or place units from 2000 to 2024, using a descriptive design.

what was measured
What we checked
  • Total fertility rate
  • Birth rate crude
  • Lfp 25 34 female
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_korea_fertility_cliff_2015_2024
1007550250200020122024KORJPNITAESPGRCPRTDEU
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show total_fertility_rate across 10 sampled countries over 2000–2024.
The shapes above are stylised — none of the lines are real data.
Placeholder for demo_korea_fertility_cliff_2015_2024. Published chart will be generated from engine/runs/demo_korea_fertility_cliff_2015_2024/chart_data.json.

Pre-registration

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

South Korea experienced a "fertility cliff" 2015-2024 (TFR falling from ~1.24 to <0.8), globally unprecedented in peacetime. The hypothesis predicts (a) Korea's TFR decline exceeds 3 standard deviations relative to OECD-comparator decadal changes, (b) the decline is concentrated in metropolitan/Seoul cohorts, and (c) early signals of working- age contraction are visible in 2020-2024 labour-market participation among 25-34 year olds.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if Korea's TFR change 2015-2024 is at least 3 SD below comparator-panel mean decadal change AND TFR end-point < 0.85. REFUTED if Korea is within 2 SD of comparators or TFR did not fall below 0.9.

formal test & threshold
test:      korea_tfr_zscore_against_comparator_panel
threshold: korea_tfr_zscore <= -3.0 AND korea_tfr_2024 < 0.85

Method

Template
descriptive
Sample
10 countries · 2000 – 2024
Evidence type
descriptive

Time-series description of Korea TFR vs comparator panel; report decadal changes and z-scores against OECD comparator distribution. No causal claim; this is a pattern-recognition spec to anchor downstream causal hypotheses.

Data

VariableSourceTransform
total_fertility_rate
outcome
world_bank_wdi:SP.DYN.TFRT.INtier 2
level
birth_rate_crude
outcome
world_bank_wdi:SP.DYN.CBRT.INtier 2
level
lfp_25_34_female
outcome
ilostat:EAP_2WAP_SEX_AGE_RTtier 2
level
gdp_per_capita_ppp
control
world_bank_wdi:NY.GDP.PCAP.PP.KDtier 2
log

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — demo_korea_fertility_cliff_2015_2024

Verdict: PARTIAL — shape=panel_summary, |Δ_log|=0.444, ratio=0.642; claim direction ambiguous

Pre-registration

  • Claim: South Korea experienced a "fertility cliff" 2015-2024 (TFR falling from ~1.24 to <0.8), globally unprecedented in peacetime. The hypothesis predicts (a) Korea's TFR decline exceeds 3 standard deviations relative to OECD-comparator decadal changes, (b) the decline is concentrated in metropolitan/Seoul cohorts, and (c) early signals of working- age contraction are visible in 2020-2024 labour-market participation among 25-34 year olds.
  • Falsification rule: SUPPORTED if Korea's TFR change 2015-2024 is at least 3 SD below comparator-panel mean decadal change AND TFR end-point < 0.85. REFUTED if Korea is within 2 SD of comparators or TFR did not fall below 0.9.
  • Falsification test: korea_tfr_zscore_against_comparator_panel

Comparison

  • shape: panel_summary
  • treatment_country: KOR
  • treatment_value: 0.8016666666666666
  • donor_pool_median: 1.2491666666666665
  • ratio: 0.6417611741160775
  • log_diff: -0.44353904743689115
  • n_donor_countries: 8
  • end_year_window: [2019, 2024]

Variables resolved

  • world_bank_wdi:SP.DYN.TFRT.IN → total_fertility_rate (outcome, publisher=world_bank_wdi, n=16998)
  • ilostat:EAP_2WAP_SEX_AGE_RT → lfp_25_34_female (outcome, publisher=ilostat, n=7704)
  • world_bank_wdi:NY.GDP.PCAP.PP.KD → gdp_per_capita_ppp (controls, publisher=world_bank_wdi, n=8360)

Variables missing data

  • world_bank_wdi:SP.DYN.CBRT.IN (outcome, name=birth_rate_crude)

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.