The rest of the world has some stake in how the UK’s planned exit from the EU (Brexit) is achieved, but it is a much more important matter for the UK economy. The issues to be managed are myriad, involving three main problems. The first is which estimates of the economic impact of Brexit should be believed. Of the few genuinely quantitative attempts, the main contenders have been authored by the UK Treasury, LSE, OECD and a group of 15 academic commentators – ‘Economists for Free Trade’. The latter have estimated the greatest potential gains. The second is the choice between a ‘soft’ and a ‘hard’ Brexit. Neither term has been precisely expressed. Mostly, the difference is the degree to which the UK might choose unilateral free trade with all nations. WTO rules may be central. The third issue is coherence of decision making processes. Some observers doubt such complexity could be handled well by elected governments.