“Economist John Springford on how he modelled what the UK would look like had it voted Remain.” https://www.newstatesman.com/politics/brexit/2023/09/john-springford-britain-remain-eu
“It was one of the most significant questions posed to the British public in the 21st century. Leave, or Remain?”…
“Had the UK voted to remain in the EU in June 2016, its trade would be significantly higher.” https://www.cer.eu/insights/cost-brexit-march-2021