Ten Years After Brexit Vote, U.K. Economy Is Between 6% and 8% Smaller Than It Would Have Been, Study Finds
A decade after Britain voted to leave the European Union, economists at Stanford, the Bank of England, King's College London and the University of Nottingham estimate that by the end of 2025 the U.K. economy was between 6% and 8% smaller than it would have been under a remain outcome. The paper, updated this month, draws on a full ten years of post-referendum data and finds the damage accumulated more slowly — and more persistently — than most forecasters anticipated. FactSet calculations show U.K. GDP grew roughly 13% since the vote, less than half the pace recorded by the United States over the same span.
A decade after Britain voted to leave the European Union, economists at Stanford, the Bank of England, King's College London and the University of Nottingham estimate that by the end of 2025 the U.K. economy was between 6% and 8% smaller than it would have been under a remain outcome. The paper, updated this month, draws on a full ten years of post-referendum data and finds the damage accumulated more slowly — and more persistently — than most forecasters anticipated. FactSet calculations show U.K. GDP grew roughly 13% since the vote, less than half the pace recorded by the United States over the same span.
Investment Bore the Deepest Scar
Business investment absorbed the sharpest hit in the study's estimates. The authors calculate that capital spending ran between 12% and 13% below the counterfactual by the end of the period, a gap that widened gradually across the full decade rather than crystallising at any single point. The mechanism was layered: companies deferred investment while policy uncertainty dragged on, senior executives spent years managing Brexit logistics rather than growth strategy, and the firms most deeply integrated with European supply chains and distribution networks suffered disproportionately.
Employment and productivity each fell as much as 4% below what the authors model as the alternative path, compounding the output shortfall. The paper characterises the losses as overlapping rather than sequential — trade friction, reduced labour mobility and sustained uncertainty reinforcing one another over time.
Forecasters Were Right, Then Surprised
Economists who warned before the 2016 referendum of near-term costs proved broadly correct through the first five years, according to the paper's authors. What the pre-vote models underestimated was the degree to which costs would continue accumulating through a full decade. The authors note in the paper that few analysts anticipated how durable the drag from trade barriers and policy uncertainty would prove once the initial adjustment period ended.
Structural Overhang Remains
Axios reporter Zach Basu summarised the current position as Britain stuck in a low-growth cycle carrying trade friction, elevated prices, strained public services and an electorate with diminished tolerance for further policy disruption. The research frame is explicitly counterfactual — comparing realised outcomes against a modelled path where the 2016 vote went the other way — which means the estimates capture foregone growth rather than an outright contraction. Still, a gap of 6% to 8% in the size of a major economy, compounding across a decade, represents a structural weight that fiscal or monetary policy alone cannot quickly offset.
The study adds quantitative depth to what has become a settled empirical debate: the voluntary erection of trade barriers, the restriction of cross-border labour flows and years of unresolved policy uncertainty each carry measurable costs. Britain ran all three simultaneously.