IESET.
Hypotheses·energy·nuclear_share_fossil_electricity_panel_1985_2024

In countries where nuclear power's share of electricity generation rose materially after 1985, fossil-fuel electricity share usually fell.

The pre-registered descriptive-panel test selects countries with at least a 5 percentage-point increase in nuclear electricity share between their first and last available observations in 1985-2024, then asks whether at least 75% of those countries experienced a fossil-fuel electricity-share decline of at least 5 percentage points and whether the median fossil-share change was at most -10 percentage points.

SUPPORTEDengine/runs/nuclear_share_fossil_electricity_panel_1985_2024

supported

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

In plain terms, this asks whether nuclear electricity share is actually linked to better or worse fossil electricity share from 1985 to 2024.

plain answer

The data clearly moved in the predicted direction. supported

why it matters

This matters because energy claims should change belief only when they survive a pre-declared empirical test.

how the test works

It compares 9 country or place units from 1985 to 2024, using a descriptive design.

what was measured
What changed
  • Nuclear electricity share
What we checked
  • Fossil electricity share
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/nuclear_share_fossil_electricity_panel_1985_2024
1007550250198520052024AREBGRBLRCZEPAKROURUS
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show fossil_electricity_share across 9 sampled countries over 1985–2024.
The shapes above are stylised — none of the lines are real data.
Placeholder for nuclear_share_fossil_electricity_panel_1985_2024. Published chart will be generated from engine/runs/nuclear_share_fossil_electricity_panel_1985_2024/chart_data.json.

Who has skin in the game — schools predicting on this

1 school 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.

Empirical Pragmatist (the framework's house position)wins if SUPPORTEDschool supported

Pre-registration

pre-registered
first-spec commit 6553077 · 2026-05-01T22:29:35Z

In countries where nuclear power's share of electricity generation rose materially after 1985, fossil-fuel electricity share usually fell. The pre-registered descriptive-panel test selects countries with at least a 5 percentage-point increase in nuclear electricity share between their first and last available observations in 1985-2024, then asks whether at least 75% of those countries experienced a fossil-fuel electricity-share decline of at least 5 percentage points and whether the median fossil-share change was at most -10 percentage points.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if at least 75% of countries with nuclear-share increases >= 5pp have fossil-share declines <= -5pp and the median fossil-share change is <= -10pp. REFUTED if fewer than 50% have fossil-share declines <= -5pp or the median fossil-share change is non-negative. Otherwise PARTIAL.

formal test & threshold
test:      nuclear_share_increase_fossil_share_endpoint_change
threshold: pass_rate >= 0.75 AND median_fossil_share_change_pp <= -10

Method

Template
descriptive
Clustering
none
Sample
9 countries · 1985 – 2024
Evidence type
descriptive

Custom replication script joins OWID nuclear and fossil electricity-share panels by country-year, selects countries with nuclear-share increases of at least 5 percentage points, and evaluates the corresponding fossil-share endpoint changes.

Data

VariableSourceTransform
fossil_electricity_share
outcome
owid:share-electricity-fossil-fuelstier 2
endpoint percentage-point change
nuclear_electricity_share
treatment
owid:share-electricity-nucleartier 2
endpoint percentage-point change

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card - nuclear_share_fossil_electricity_panel_1985_2024

Verdict: supported - 9 of 9 nuclear-buildout countries pass; median fossil-share change -32.2pp

Endpoint Test

Countries enter the test if nuclear electricity share rose by at least 5pp over their 1985-2024 window. Support requires at least 75% of those countries to show fossil electricity share declines of at least 5pp, with median fossil-share change <= -10pp.

| ISO3 | Country | Window | Nuclear change pp | Fossil change pp | Pass | |---|---|---:|---:|---:|:---:| | ARE | United Arab Emirates | 1985-2024 | 22.9 | -31.7 | yes | | BGR | Bulgaria | 1990-2024 | 6.2 | -32.2 | yes | | BLR | Belarus | 2000-2024 | 34.2 | -37.2 | yes | | CZE | Czechia | 1990-2024 | 20.6 | -35.6 | yes | | PAK | Pakistan | 2000-2024 | 12.5 | -23.8 | yes | | ROU | Romania | 1990-2024 | 20.7 | -49.5 | yes | | RUS | Russia | 1985-2024 | 7.5 | -9.0 | yes | | SVK | Slovakia | 1990-2024 | 14.5 | -31.2 | yes | | UKR | Ukraine | 1985-2022 | 36.2 | -48.6 | yes |

Interpretation

This is a descriptive substitution-pattern test. It does not isolate nuclear policy from demand growth, hydro/renewables, or broader energy-system reforms.

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.