IESET.
Hypotheses·labour·demo_us_hart_celler_1965_legacy

The 1965 US Hart-Celler immigration reform replaced national-origin quotas with a family-reunification + skill-based system, producing a multi-decade shift in the composition and scale of US migrant inflows.

The hypothesis tests whether the post-1965 immigrant cohort delivered measurable contributions to (a) US working-age population growth above the trajectory implied by pre-1965 rules, and (b) labour-force participation rates and per-capita output, controlling for natural population growth.

PARTIALengine/runs/demo_us_hart_celler_1965_legacy

PARTIAL — shape=ITS, mean_gap=+5.192, z=+46; 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 hart celler indicator is actually linked to better or worse foreign born population share from 1950 to 2023.

plain answer

The evidence is suggestive but not decisive. shape=ITS, mean_gap=+5.192, z=+46; 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 1 country or place units from 1950 to 2023, using a event study design.

what was measured
What changed
  • Hart celler indicator
What we checked
  • Foreign born population share
  • 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_us_hart_celler_1965_legacy
1007550250195019872023USA
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show foreign_born_population_share across 1 sampled countries over 1950–2023.
The shapes above are stylised — none of the lines are real data.
Placeholder for demo_us_hart_celler_1965_legacy. Published chart will be generated from engine/runs/demo_us_hart_celler_1965_legacy/chart_data.json.

Pre-registration

registration ordering unverified
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z
run generated · 2026-04-30T10:51:12Z
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.

The 1965 US Hart-Celler immigration reform replaced national-origin quotas with a family-reunification + skill-based system, producing a multi-decade shift in the composition and scale of US migrant inflows. The hypothesis tests whether the post-1965 immigrant cohort delivered measurable contributions to (a) US working-age population growth above the trajectory implied by pre-1965 rules, and (b) labour-force participation rates and per-capita output, controlling for natural population growth.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if the foreign-born share trajectory shows a structural break at 1965/1968 with post-break slope exceeding pre-break slope by at least 0.05 pp/yr, AND the cumulative contribution to US working-age share by 2020 exceeds 3 percentage points versus a no-Hart-Celler counterfactual. REFUTED if no detectable break or cumulative working-age contribution < 1pp.

formal test & threshold
test:      event_study_hart_celler_break_with_counterfactual_simulation
threshold: break_test_p < 0.05 AND cumulative_wap_contribution_2020 >= 3.0

Method

Template
event_study
Sample
1 countries · 1950 – 2023
Evidence type
associational

Event-study design around 1965/1968 with single-treated-unit (US); use long pre-period 1950-1965 as baseline. Report break-test on foreign-born share trajectory.

Data

VariableSourceTransform
foreign_born_population_share
outcome
un_desa:international_migrant_stocktier 2
level
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
hart_celler_indicator
treatment
constructed:indicator = 1 for years >= 1968 (effective date of 1965 reform)tier 5
indicator
total_fertility_rate
control
world_bank_wdi:SP.DYN.TFRT.INtier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — demo_us_hart_celler_1965_legacy

Verdict: PARTIAL — shape=ITS, mean_gap=+5.192, z=+46; claim direction ambiguous

Pre-registration

  • Claim: The 1965 US Hart-Celler immigration reform replaced national-origin quotas with a family-reunification + skill-based system, producing a multi-decade shift in the composition and scale of US migrant inflows. The hypothesis tests whether the post-1965 immigrant cohort delivered measurable contributions to (a) US working-age population growth above the trajectory implied by pre-1965 rules, and (b) labour-force participation rates and per-capita output, controlling for natural population growth.
  • Falsification rule: SUPPORTED if the foreign-born share trajectory shows a structural break at 1965/1968 with post-break slope exceeding pre-break slope by at least 0.05 pp/yr, AND the cumulative contribution to US working-age share by 2020 exceeds 3 percentage points versus a no-Hart-Celler counterfactual. REFUTED if no detectable break or cumulative working-age contribution < 1pp.
  • Falsification test: event_study_hart_celler_break_with_counterfactual_simulation
  • Event year: 1965

Estimate

  • shape: single_country_its
  • country: USA
  • event_year: 1965
  • n_pre: 5
  • n_post: 59
  • pre_trend_slope: 0.01936765605916139
  • pre_trend_intercept: 21.801446368483525
  • pre_residual_sd: 0.1136903765215298
  • end_year: 2023
  • end_year_actual: 64.9735428685564
  • end_year_counterfactual: 60.98221457616702
  • end_year_gap: 3.991328292389376
  • mean_post_gap: 5.192489061483069
  • z_end: 35.107002144843186
  • z_mean: 45.67219513517713
  • post_period_years: [1965, 2023]

Variables resolved

  • world_bank_wdi:SP.POP.1564.TO.ZS → working_age_population_share (outcome, publisher=world_bank_wdi, n=16965)
  • world_bank_wdi:NY.GDP.PCAP.KD.ZG → real_gdp_per_capita_growth (outcome, publisher=world_bank_wdi, n=13897)

Variables missing data

  • un_desa:international_migrant_stock (outcome, name=foreign_born_population_share)
  • constructed: indicator = 1 for years >= 1968 (effective date of 1965 reform) (treatment, name=hart_celler_indicator)
  • world_bank_wdi:SP.DYN.TFRT.IN (controls, name=total_fertility_rate)

Generated by scripts/run_event_study.py at 2026-04-30T10:51:12+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.