Bounded rationality and the Brexit negotiations: Why Britain failed to understand the EU

Research on the Brexit negotiations has linked the problems faced by Britain to flawed assumptions in the UK’s perception of EU interests. These include the ideas that the EU would be open to compromise on key principles, that it would offer the UK a bespoke relationship, that national capitals would respond favourably to bilateral initiatives, and that EU unity would not hold. Yet the origins of these assumptions have been subject to little systematic scrutiny. How did such wrong-headed assumptions about the EU’s interests emerge? Drawing on insights from bounded rationality we identify three aspects of the decision-making environment linked with biased thinking: (1) ill-fitting routines and lessons, (2) a lack of decision-making openness, and (3) a lack of EU expertise and contact. We demonstrate our argument using data obtained from interviews in Brussels and London in 2017-18 and accounts of those involved in the decisions.