The question is not whether Brexit will cost the UK in economic terms but how much

For over two years, a research team at the Centre for Economic Performance (CEP) has been studying the likely impact of the UK leaving the European Union. Their latest report focuses on the impact of ‘Brexit’ through changing trade patterns. Under ‘optimistic’ assumptions, there is a fall in national income of 1.3 per cent (about £850 per household). Under ‘pessimistic’ assumptions, this doubles to 2.6 per cent. When the dynamic effects of higher trade costs on productivity are included, the cost may rise to between 6.3 per cent and 9.5 per cent in the long run