A decade after the United Kingdom voted to leave the European Union in June 2016, new research suggests the decision has carried a steep economic price. Thomas Sampson, an associate professor of economics at the London School of Economics (LSE), estimates that Brexit may have reduced UK GDP per head by as much as 8% by early 2025 — equivalent to a loss of roughly £3,300 per person annually. The finding draws on analysis of three key channels: a sharp fall in sterling that pushed up import prices and consumer costs, prolonged investment uncertainty during years of political turmoil, and the trade barriers introduced when the UK left the EU's single market in 2021 — which are estimated to have cut UK goods exports to the EU by 10–15% and reduced business investment by around 15% in 2024.