The macro impact of Brexit — interactive counterfactual

Replication of the cross-country comparison in Section 3 of Bloom, Bunn, Mizen, Smietanka & Thwaites (NBER w34459). Vary the weighting scheme, drop countries, or specify your own weights to see how the estimated UK GDP-per-capita gap changes.

Weighting scheme

Comparator countries

Untick to exclude a country (its weight is removed and the metric is recomputed over the remaining countries). In Custom mode, edit the weight column directly — values are auto-normalised.

Use Country 2015 GDP
$bn
Distance
km from London
UK trade
£bn
Weight
%

Estimated UK GDP-per-capita gap

UK (2016Q1=100)
Counterfactual, same period
Gap (UK vs counterfactual)
Countries used / weights sum to
Notes
  • UK GDP-per-capita uses ONS series ABMI (chained-volume measure, seasonally adjusted) divided by population spliced from Eurostat (2004–2019) and World Bank (2020–); other European countries from Eurostat namq_10_gdp (chain-linked volume index, 2015 = 100, SA); US/Canada/Japan from OECD QNA chain-linked volume.
  • Paper's headline is −8% (range −6% to −10%, year to 2025Q1) across the five weighting schemes. Cyprus and Malta are excluded by default following the paper. The headline window above adjusts automatically — with current data it covers the most recent four quarters (year to 2025Q4).
  • Data-vintage caveat: the paper's UK index at year-to-2025Q1 (104.3) is ~1 pp lower than the current ONS series (~105.3, 2016Q1 = 100), because ONS Blue Book 2025 (September 2025) revised UK GDP up by ~0.5 pp/year over 2021–2024 — after the paper's underlying data was assembled. This app uses post-revision ONS data, so each scheme's estimated gap appears ~1 pp narrower than the paper's stated figures. Comparator-side methodology matches the paper to within ~0.3 pp per scheme once this UK level shift is taken out.
  • For the synthetic-control scheme this app uses the paper's published weights (USA 61.4%, EST 10.9%, GRC 9.5%, ITA 6.7%, IRL 4.4%, LVA 3.4%, ISL 3.0%, HUN 0.7%). When countries are dropped the remaining weights are proportionally rescaled — this is an approximation; a true re-optimisation with predictors is not done in-browser.
  • Ireland: per the paper, this app uses Modified Final Domestic Demand (CSO NAQ05, code 0155, constant prices, seasonally adjusted) in place of headline GDP, to remove the volatility caused by multinational corporations' intangible-asset and aircraft-leasing flows.