In the UK, economic performance has been sluggish since its departure from the EU in January 2020, with experts facing a significant challenge in isolating the impact of Brexit from the subsequent COVID-19 outbreak that swept across Europe in late spring 2020.
Estimates of Brexit's economic impact on the UK have been compiled by various authorities.
Related ↗Economic growth in Northern Ireland outpaces rest of the UK post-Brexit.The U.S. National Bureau of Economic Research has a notable publication date in November 2025.
Estimates suggest that Brexit will likely shave off between 6 and 8 percent from the UK's GDP.
Read next ↗British inflation rate remains steady at a 13-month low beforehand.Economic output declined by that margin.
Economic investment declined sharply.
Uncertainty surrounding Brexit is dampening investment, as businesses anticipate reduced consumer demand and sluggish productivity growth amidst the diversion of resources.
The synthetic counterfactual UK is constructed from a weighted average of several countries, with the US contributing 61%, Estonia 11%, Greece 10% and Italy 7%. Other nations are also factored in to replicate pre-Brexit economic metrics.
Economists from various institutions, including Stanford University, have collaborated with counterparts at the Bank of England, Deutsche Bundesbank and others.
Julian Jessop, a prominent economist at the Institute of Economic Affairs.
The NBER's approach is criticized for overemphasizing US economic indicators and assuming that the UK's pre-Brexit peers would remain suitable partners post-Brexit.
The United States' economic expansion has diverged significantly from other major economies since 2020, whereas the UK's GDP per capita growth mirrors that of Germany and France.
Achieving an 8% boost in GDP would necessitate the UK surpassing its peers by a considerable margin.
UK job market resilience is unlikely to significantly improve within the EU framework.
Investment growth slows temporarily due to Brexit uncertainty.
The UK Office for Budget Responsibility released a report in July 2025.
Estimates suggest that a post-Brexit trade deal could lead to a 4% decrease in long-term productivity.
By the time a post-Brexit trade agreement took effect in January 2021, nearly half of Britain's economic losses were already evident.
The UK's trade with the EU is projected to decline by a significant 15% over time.
The UK's new trade agreements with nations outside the EU are unlikely to significantly affect.
Historic trade agreements have been scrutinized in depth calculations.
The National Institute of Economic and Social Research made predictions in April 2025.
Estimates suggest a 2-3 percent decline in GDP per capita and labor productivity by 2023.
Business investment in the UK is forecasted to drop significantly between now and 2023. By that year, a decline of 12-13 percent can be expected. However this downward trend is anticipated to slow down slightly over the next decade, with estimates suggesting a reduction of only 7-8 percent by 2035.
The economic effects of Brexit are simulated through decreased trade, heightened perpetual uncertainty, and lower productivity levels within NIESR's established economic framework.
UK exporters face heightened trading expenses, causing a decline in high-productivity companies engaging in international trade. Conversely, the diminished EU competition enables lower-productivity businesses to thrive within the domestic market.
The Centre for European Reform's John Springford provided insights in December 2022.
As of June 2022, Britain's economy was found to be 5.5% smaller than it would have been had it remained within the European Union.
Investment decline reaches 11%.
The UK's exports have suffered a 7% decline.
The UK's reduced economic size is projected to result in a loss of approximately forty billion pounds.
The subsequent NBER study employed a comparable approach.
The exchange rate is set at one US dollar equaling approximately 0.7448 British pounds.
