Why did the UK leave the EU? : the state of the science of explaining Brexit

Abstract

Explaining why the United Kingdom (UK) left the European Union (EU) has become something of a cottage industry since 2016. Not only was the outcome a notable electoral upset, a constitution rupture for the UK and a clear vote of no confidence for the EU, but the campaign exposed seemingly hitherto hidden forces in society, existential questions for Britain and, arguably, advanced post-industrial democracies elsewhere. Moreover, the UK’s long and difficult relationship with ‘Europe’ and the myriad dramatic political and economic events in the decade prior to the referendum offer observers a large choice of potential causal explanations for why Brexit happened. In this chapter I attempt to critically overview and connect this literature. I argue that there are roughly four categories of explanation for Brexit, each of which includes multiple distinct theoretical contributions. First, historical and identitarian explanations have explained Brexit as the result of Britain’s long-term discomfort with integration resulting from a lack of European identity, Eurosceptic political and media elite and, ultimately, a distinct political history, culture and geography. Second, socio-political explanations have focused on social transformations in the UK and beyond, notably in terms of immigration, the so-called ‘losers of globalisation’ or ‘left behind’ and an emerging ‘value divide’ and ‘cultural backlash’ based on tertiary education, amongst other things. Third, a range of explanations have argued that the vote was a proxy for discontent over other issues beyond Britain’s relationship with the EU, primarily opposition to austerity, anti-establishment sentiment, non-political psychological motivations and English nationalism. Fourth, more proximate explanations have focused on the campaign itself – notably the weaknesses of the Remain campaign and the strengths of the Leave campaign. Despite being theoretically distinct, the numerous mechanisms within each category tend to have common strengths and weaknesses. Finally, I argue that, despite a rich literature that includes robust advances, there are important shortcomings to our understanding of why the UK left the EU, particularly (1) in terms of understanding over-time variation in British attitudes to membership and (2) in considering retrospective voting towards the object of the referendum, the EU itself.