根据伦敦政治经济学院经济绩效研究中心的估算，英国因减少对欧盟贸易而产生的长期成本可能相当于GDP的9.5 ％ ， 而外国投资下降的影响则可能超过GDP的3.4 ％ 。
The London School of Economics’ Centre for Economic Performance calculates that the long-term costs to Britain of lower trade with the EU could be as high as 9.5% of GDP, while the fall in foreign investment could cost 3.4% of GDP or more.