IESET.
Hypotheses·labour·demo_marriage_age_fertility_growth

Across countries 1980-2023, rising age at first marriage is associated with declining total fertility rate, and through that channel, with shifts in working-age trajectories that propagate to per-capita growth 25-30 years later.

The hypothesis predicts (a) panel association between mean age at first marriage and TFR is negative, (b) the marriage-age- to-TFR relationship is partly mediated by female tertiary attainment, and (c) implied long-run per-capita growth contribution via working-age share is detectable but small (<0.2pp annualised) on its own.

REFUTEDengine/runs/demo_marriage_age_fertility_growth

REFUTED — coef=+0.02457 (sign opposite claim -), p=0.0363

confidence cueThis test cuts against the claim as written or misses its pre-declared threshold.

policy briefNeeds review

In ordinary language

In plain terms, this asks whether mean age first marriage female is actually linked to better or worse total fertility rate from 1980 to 2023.

plain answer

The data did not support the prediction. coef=+0.02457 (sign opposite claim -), p=0.0363

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 30 country or place units from 1980 to 2023, using a panel fe decomposition design, with fixed effects for country and year.

what was measured
What changed
  • Mean age first marriage female
Possible pathway
  • Tertiary attainment female
  • Female lfp
What we checked
  • Total fertility rate
  • 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_marriage_age_fertility_growth
1007550250198020022023USAGBRDEUFRAITAESPJPN
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show total_fertility_rate across 30 sampled countries over 1980–2023.
The shapes above are stylised — none of the lines are real data.
Placeholder for demo_marriage_age_fertility_growth. Published chart will be generated from engine/runs/demo_marriage_age_fertility_growth/chart_data.json.

Pre-registration

pre-registered
first-spec commit 098ce96 · 2026-04-30T12:57:33Z
run generated · 2026-06-29T17:53:35Z

Across countries 1980-2023, rising age at first marriage is associated with declining total fertility rate, and through that channel, with shifts in working-age trajectories that propagate to per-capita growth 25-30 years later. The hypothesis predicts (a) panel association between mean age at first marriage and TFR is negative, (b) the marriage-age- to-TFR relationship is partly mediated by female tertiary attainment, and (c) implied long-run per-capita growth contribution via working-age share is detectable but small (<0.2pp annualised) on its own.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if (a) coefficient on marriage age is negative on TFR at p<0.05, (b) female tertiary attainment absorbs at least 30% of the marriage-age coefficient on TFR (i.e. a substantial mediation share), AND (c) implied per-capita-growth contribution from marriage-age channel is non-zero in stage-2. REFUTED if any of (a)-(c) fails or mediation share by tertiary attainment is below 10%.

formal test & threshold
test:      panel_fe_decomp_marriage_age_fertility_growth
threshold: coef_marriage_age_on_tfr < 0 AND p < 0.05 AND tertiary_mediation_share >= 0.30

Method

Template
panel_fe_decomposition
Fixed effects
country, year
Clustering
country
Sample
30 countries · 1980 – 2023
Evidence type
associational

Two-stage: stage-1 marriage-age → TFR (with female tertiary mediation); stage-2 implied TFR shift → working-age share at lag 25-30 → per-capita growth contribution.

Data

VariableSourceTransform
total_fertility_rate
outcome
world_bank_wdi:SP.DYN.TFRT.INtier 2
level
real_gdp_per_capita_growth
outcome
world_bank_wdi:NY.GDP.PCAP.KD.ZGtier 2
level
mean_age_first_marriage_female
treatment
un_desa:singulate_mean_age_marriage_femaletier 2
level
tertiary_attainment_female
channel
world_bank_wdi:SE.TER.CUAT.BA.FE.ZStier 2
level
female_lfp
channel
world_bank_wdi:SL.TLF.CACT.FE.ZStier 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_marriage_age_fertility_growth

Verdict: REFUTED — coef=+0.02457 (sign opposite claim -), p=0.0363

Pre-registration

  • Claim: Across countries 1980-2023, rising age at first marriage is associated with declining total fertility rate, and through that channel, with shifts in working-age trajectories that propagate to per-capita growth 25-30 years later. The hypothesis predicts (a) panel association between mean age at first marriage and TFR is negative, (b) the marriage-age- to-TFR relationship is partly mediated by female tertiary attainment, and (c) implied long-run per-capita growth contribution via working-age share is detectable but small (<0.2pp annualised) on its own.
  • Falsification rule: SUPPORTED if (a) coefficient on marriage age is negative on TFR at p<0.05, (b) female tertiary attainment absorbs at least 30% of the marriage-age coefficient on TFR (i.e. a substantial mediation share), AND (c) implied per-capita-growth contribution from marriage-age channel is non-zero in stage-2. REFUTED if any of (a)-(c) fails or mediation share by tertiary attainment is below 10%.
  • Falsification test: panel_fe_decomp_marriage_age_fertility_growth

Estimate

  • Method: linearmodels.PanelOLS
  • Coefficient (treatment): +0.02457
  • Std error: 0.01166
  • p-value: 0.0363
  • Observations: 268, countries: 23
  • Within R²: -1.08
  • Fixed effects: entity=True, time=True
  • Clustering: country

Variables resolved

  • world_bank_wdi:SP.DYN.TFRT.IN → total_fertility_rate (outcome, publisher=world_bank_wdi, n=14445)
  • world_bank_wdi:NY.GDP.PCAP.KD.ZG → real_gdp_per_capita_growth (outcome, publisher=world_bank_wdi, n=13897)
  • world_bank_wdi:SE.TER.CUAT.BA.FE.ZS → tertiary_attainment_female (decomposition_channels, publisher=world_bank_wdi, n=1401)
  • world_bank_wdi:SL.TLF.CACT.FE.ZS → female_lfp (decomposition_channels, publisher=world_bank_wdi, n=8302)
  • world_bank_wdi:NY.GDP.PCAP.PP.KD → gdp_per_capita_ppp (controls, publisher=world_bank_wdi, n=8325)

Variables missing data

  • un_desa:singulate_mean_age_marriage_female (treatment, name=mean_age_first_marriage_female) — vintage not on disk

Generated by scripts/run_panel_fe.py at 2026-06-29T17:53:35+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.