IESET.
Hypotheses·trade·trade_lib_uk_brexit_2020_export_response

The UK's exit from the EU single market (effective 2021-01-01 end of transition) reduced UK trade-openness and merchandise exports relative to a synthetic-control donor pool of European comparator economies.

The post-2021 window is contaminated by COVID-19 and Russia-Ukraine war shocks, but the UK-specific underperformance pattern is hypothesised to be detectable against the synthetic counterfactual.

PARTIALengine/runs/trade_lib_uk_brexit_2020_export_response

PARTIAL — mean_gap=-65.92, |gap|/pre_sd=25, p_perm=0.333 (gap below 0.5×pre_sd or placebo p≥0.10)

confidence cueThe result is useful, but not decisive. Treat it as a clue, not a settled conclusion.

policy briefMixed or noisy

In ordinary language

When countries open more of the economy to trade and competition, do people end up with better long-run income or productivity outcomes?

plain answer

The evidence is suggestive but not decisive. mean_gap=-65.92, |gap|/pre_sd=25, p_perm=0.333 (gap below 0.5×pre_sd or placebo p≥0.10)

why it matters

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

how the test works

It compares 12 country or place units from 2010 to 2024, using a synthetic control design.

what was measured
What changed
  • Brexit indicator
What we checked
  • Trade openness pct income
  • Merchandise exports pct income
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

0 input datasets, 0 unresolved missing series, provenance status: no input vintages recorded.

Results

engine/runs/trade_lib_uk_brexit_2020_export_response
1007550250201020172024GBRDEUFRAITAESPNLDBEL
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show trade_openness_pct_gdp across 12 sampled countries over 2010–2024.
The shapes above are stylised — none of the lines are real data.
Placeholder for trade_lib_uk_brexit_2020_export_response. Published chart will be generated from engine/runs/trade_lib_uk_brexit_2020_export_response/chart_data.json.

Pre-registration

registration ordering unverified
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z
run generated · 2026-05-15T20:30:51Z
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 UK's exit from the EU single market (effective 2021-01-01 end of transition) reduced UK trade-openness and merchandise exports relative to a synthetic-control donor pool of European comparator economies. The post-2021 window is contaminated by COVID-19 and Russia-Ukraine war shocks, but the UK-specific underperformance pattern is hypothesised to be detectable against the synthetic counterfactual.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if SC gap on trade-openness for GBR by 2024 is negative by >=5 pp. PARTIAL if negative but smaller. REFUTED if positive.

formal test & threshold
test:      synthetic_control_uk_brexit_2021
threshold: PRIMARY: SC_gap(trade_openness, 2024) <= -5 pp. INFORMATIVE: ex-2016-2019 robustness retains negative sign.

Method

Template
synthetic_control
Clustering
country
Sample
12 countries · 2010 – 2024
Evidence type
causal

Synthetic-control estimator for the UK against European- comparator donor pool. Pre-treatment 2010-2019 (avoiding Brexit-vote anticipation effect from 2016 in a robustness check). Post-treatment 2021-2024.

Data

VariableSourceTransform
trade_openness_pct_gdp
outcome
world_bank_wdi:NE.TRD.GNFS.ZStier 2
level
merchandise_exports_pct_gdp
outcome
world_bank_wdi:NE.EXP.GNFS.ZStier 2
level
brexit_indicator
treatment
constructed:indicator = 1 for GBR from 2021-01-01 (end of transition)tier 5
indicator
log_gdp_pc_pretreatment
control
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log_level_at_treatment_minus_1
real_effective_exchange_rate
control
imf:REERtier 2
log

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — trade_lib_uk_brexit_2020_export_response

Verdict: PARTIAL — mean_gap=-65.92, |gap|/pre_sd=25, p_perm=0.333 (gap below 0.5×pre_sd or placebo p≥0.10)

Pre-registration

  • Claim: The UK's exit from the EU single market (effective 2021-01-01 end of transition) reduced UK trade-openness and merchandise exports relative to a synthetic-control donor pool of European comparator economies. The post-2021 window is contaminated by COVID-19 and Russia-Ukraine war shocks, but the UK-specific underperformance pattern is hypothesised to be detectable against the synthetic counterfactual.
  • Falsification rule: SUPPORTED if SC gap on trade-openness for GBR by 2024 is negative by >=5 pp. PARTIAL if negative but smaller. REFUTED if positive.

Synthetic-control estimate

  • shape: synth_did
  • treated_country: GBR
  • event_year: 2021
  • n_donors: 11
  • donor_weights (top): {'SWE': 0.4759, 'BEL': 0.2663, 'CHE': 0.2579, 'DEU': 0.0, 'FRA': 0.0}
  • pre_rmse: 54.02346645178312
  • pre_period_sd: 2.652951453474659
  • mean_post_gap: -65.92258102437334
  • end_period_gap: -64.44406892562881
  • post_period_years: [2021, 2024]
  • placebo_p_value: 0.3333333333333333
  • n_placebos: 11
  • method: synthetic-control via NNLS, permutation inference

Variables resolved

  • world_bank_wdi:NE.TRD.GNFS.ZS → trade_openness_pct_gdp (outcome, n=10714)
  • world_bank_wdi:NE.EXP.GNFS.ZS → merchandise_exports_pct_gdp (outcome, n=10904)
  • constructed: indicator = 1 for GBR from 2021-01-01 (end of transition) → brexit_indicator (treatment, n=180)
  • world_bank_wdi:NY.GDP.PCAP.KD → log_gdp_pc_pretreatment (controls, n=14066)

Generated by scripts/run_synth_did.py at 2026-05-15T20:30:51+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.