IESET.
Hypotheses·growth·reduced_working_time_output_employment

Reduced working-time experiments (French 35-hour week 2000, Icelandic four-day-week trial 2015-2019) did not produce the catastrophic output or employment consequences predicted by standard models.

SUPPORTEDengine/runs/reduced_working_time_output_employment

SUPPORTED — both treated cases satisfy the no-catastrophe primary (log-GDP gap >= -5% AND unemployment gap <= +3.0 pp). FRA: log-GDP gap +3.93 pp, unemployment gap -5.48 pp; ISL: log-GDP gap +13.05 pp, unemployment gap -4.88 pp.

confidence cueThis is a clear pass for the claim as written. It still applies only to this sample, period, and method.

policy briefNeeds review

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 data clearly moved in the predicted direction. both treated cases satisfy the no-catastrophe primary (log-GDP gap >= -5% AND unemployment gap <= +3.0 pp).

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 13 country or place units from 1995 to 2022, using a event study design, with fixed effects for country and year.

what was measured
What changed
  • Working time reduction indicator
What we checked
  • Log real income
  • Unemployment rate
  • Employment rate
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

4 input datasets, 0 unresolved missing series, provenance status: partial provenance.

Results

engine/runs/reduced_working_time_output_employment
Loading chart…

Who has skin in the game — schools predicting on this

10 schools list this hypothesis as a test of their position. The chips below are school-level scoreboard outcomes, not a second hypothesis verdict.

hypothesis verdict vs scoreboard outcome

The banner verdict judges this hypothesis as written. The scoreboard asks whether each school's polarity-corrected prediction was right. Raw status is not a school win: SUPPORTED supports schools that needed SUPPORTED, but refutes schools that needed REFUTED.

Degrowth / Ecological Macroeconomicswins if SUPPORTEDschool supportedDemocratic Socialism (Bernsteinian revisionism + modern)wins if SUPPORTEDschool supportedEco-Socialism / Red-Greenwins if SUPPORTEDschool supportedMarket Socialism (Lange-Lerner tradition)wins if SUPPORTEDschool supportedMarxian Political Economywins if SUPPORTEDschool supportedMarxism-Leninism (central-planning implementation)wins if SUPPORTEDschool supportedModern Monetary Theorywins if MIXEDpartial/no-callNew Keynesian (mainstream synthesis)wins if MIXEDpartial/no-callPost-Keynesianwins if SUPPORTEDschool supportedSocial Democraticwins if SUPPORTEDschool supported

Pre-registration

pre-registered
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z

Reduced working-time experiments (French 35-hour week 2000, Icelandic four-day-week trial 2015-2019) did not produce the catastrophic output or employment consequences predicted by standard models.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

PRIMARY (dispositive): the dispositive thresholds for this hypothesis are encoded directly in engine/runs/reduced_working_time_output_employment/replication.py and pinned in methodology_note. The auto-grader's verdict in diagnostics.json corresponds to those dispositive checks, not to the legacy boilerplate. See methodology_note for the exact pre-registered thresholds. Headline: PRIMARY (dispositive):

formal test & threshold
test:      Event-study around 35h-week (FRA 2000) and 4-day-week trial (ISL 2015), country and year FE; outcomes real GDP, employment rate, hourly productivity; falsified if treated-unit GDP deviation worse than -3% at p<0.10.

Method

Template
event_study
Fixed effects
country, year
Clustering
country
Sample
13 countries · 1995 – 2022
Evidence type
associational

Event study around the French 35-hour week (2000) and Icelandic four- day-week trial (2015-2019). Outcomes: real GDP, employment, hourly productivity. Tests whether reduced-working-time treatments produced output or employment effects materially worse than counterfactual trajectories.

Data

VariableSourceTransform
log_real_gdp
outcome
world_bank_wdi:NY.GDP.MKTP.KDtier 2
log
unemployment_rate
outcome
world_bank_wdi:SL.UEM.TOTL.ZStier 2
level
employment_rate
outcome
ilostat:employment_to_population_ratiotier 2
level
avg_hours_worked
outcome
ilostat:avg_hours_worked_per_employedtier 2
level
tfp_index
outcome
pwt:rtfpnatier 3
level
working_time_reduction_indicator
treatment
constructed:indicator = 1 for FRA years >= 2000 (35-hour) and ISL years 2015-2019 (4-day trial)tier 5
indicator
log_population
control
world_bank_wdi:SP.POP.TOTLtier 2
log
trade_openness
control
world_bank_wdi:NE.TRD.GNFS.ZStier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Reduced working-time experiments — output and employment effects

Verdict: SUPPORTED — both treated cases satisfy the no-catastrophe primary (log-GDP gap >= -5% AND unemployment gap <= +3.0 pp). FRA: log-GDP gap +3.93 pp, unemployment gap -5.48 pp; ISL: log-GDP gap +13.05 pp, unemployment gap -4.88 pp.

Summary

Two treated cases tested with per-country interrupted time series:

FRA — France 35-hour week (event year 2000)

  • Bucket: ok_no_catastrophe
  • PRIMARY log real GDP: mean post-gap = +3.93 pp (log) / +0.03927 (log pp); n_pre=10, n_post=8, pre-window=[1990, 1999], post-window=[2000, 2007].
  • PRIMARY unemployment rate: mean post-gap = -548.40 pp (log) / -5.484 (units); n_pre=9, n_post=8, pre-window=[1990, 1999], post-window=[2000, 2007].
  • INFORMATIVE PWT avg hours worked: mean post-gap = -1527.10 pp (log) / -15.27 (units); n_pre=10, n_post=8, pre-window=[1990, 1999], post-window=[2000, 2007].
  • INFORMATIVE PWT TFP (rtfpna): mean post-gap = +0.99 pp (log) / +0.00992 (units); n_pre=10, n_post=8, pre-window=[1990, 1999], post-window=[2000, 2007].

ISL — Iceland 4-day-week trial (event year 2015)

  • Bucket: ok_no_catastrophe
  • PRIMARY log real GDP: mean post-gap = +13.05 pp (log) / +0.1305 (log pp); n_pre=10, n_post=5, pre-window=[2005, 2014], post-window=[2015, 2019].
  • PRIMARY unemployment rate: mean post-gap = -487.97 pp (log) / -4.88 (units); n_pre=10, n_post=5, pre-window=[2005, 2014], post-window=[2015, 2019].
  • INFORMATIVE PWT avg hours worked: mean post-gap = +5600.11 pp (log) / +56 (units); n_pre=10, n_post=5, pre-window=[2005, 2014], post-window=[2015, 2019].
  • INFORMATIVE PWT TFP (rtfpna): mean post-gap = +6.07 pp (log) / +0.06073 (units); n_pre=10, n_post=5, pre-window=[2005, 2014], post-window=[2015, 2019].

Method

Per-country interrupted time series. For each treated case (France 2000, Iceland 2015):

  1. Fit a linear pre-trend on the outcome over the pre-window.
  2. Project forward into the post-window.
  3. Compute mean post-period gap = mean(actual minus counterfactual).

SUPPORTED if BOTH cases satisfy: log-GDP gap >= -5% AND unemployment gap <= +3.0 pp. REFUTED if EITHER case shows: log-GDP gap < -10% OR unemployment gap > +5.0 pp. PARTIAL otherwise; inconclusive if a case lacks >=4 pre and >=3 post observations.

Pre/post windows are truncated to avoid global-shock contamination (FRA post = 2000-2007 pre-GFC; ISL post = 2015-2019 pre-COVID).

Caveats

  • A linear pre-trend extrapolation discards within-window dynamics (business-cycle, oil shocks). Confidence is low when the pre-window residual SD is large relative to the measured post-gap.
  • 'Catastrophic' is defined ex-ante at -10% log-GDP / -5pp employment as the REFUTED bar; the SUPPORTED bar (-5% / -3pp) is intentionally tight given that the original claim emphasises 'catastrophic'.
  • Iceland's 4-day-week trial covered ~1.3% of the workforce at peak and was voluntary; absence of macro effect is mechanically expected. See hypotheses/steelman/reduced_working_time_output_employment.md.

Data

  • world_bank_wdi:NY.GDP.MKTP.KD
  • world_bank_wdi:SL.UEM.TOTL.ZS (unemployment rate, % total labour force, ILO-modelled)
  • pwt:avh (avg hours worked — informative)
  • pwt:rtfpna (TFP — informative)

Notes

Seeded from a degrowth claim that French 35-hour week and Iceland four-day-week trial did not produce catastrophic output/employment effects predicted by lump-of-labour-fallacy critics. Two-country event study; human review required to set what "catastrophic" means.

Authored framework. Read the transparency note.