“Just consider the following three effects of a sudden Brexit. First, the eurozone remains dependent on the City of London for financial services and especially on settlement and clearing, the plumbing of the financial system. Mark Carney, governor of the Bank of England, who is not a Brexit cheerleader, said recently there was a bigger risk of a financial crisis in the EU than in the UK. The eurozone is unfortunate in that it allowed its main financial centre to be outside its borders. There is a clear potential for blackmail here.
Second, it is trivially true that Britain has a smaller weight in eurozone trade than the eurozone has in UK trade. This is because the eurozone is bigger. But do not underestimate that manufacturing supply chains work in both directions. A sudden break could disrupt manufacturing production everywhere. Remember that a single bank, Lehman Brothers, was able to blow up the global financial system in 2008. Dynamic effects are harder to calculate than the static ones but they can be much bigger.
Third, the UK is a member of the UN Security Council, the Group of 20 advanced industrial nations, and the Group of Seven. If EU countries want to fight tax avoidance by multinational companies, manage globalisation in a fairer way, reduce greenhouse gas emissions or come up with policies to combat terrorism, they will need the UK.”
