Brexit! Grexit? Frexit? : considerations on how to explain and measure the propensities of member states to leave the European Union

Abstract

Ever since the United Kingdom (UK) decided to leave the European Union (EU) in June 2016, one question has been on the minds of many Europeans: which other member states could leave the EU in the years ahead? In this paper, I develop an ‘exit index’ to measure each individual member state’s propensity to leave the EU, based on conjectures on how member states would generally decide to leave. After a discussion of methodological choices connected to composite indices, I use this index to define the ‘cores of Europe’. My results show that the UK is an outlier in terms of exit propensity. The only other country giving cause for some concern is Italy. Still, while practically all member states other than the UK are far from leaving the EU, the exit index brings to light substantial variation among them. Moreover, the exit index allows constant updating of exit propensities and could thus serve as an ‘early-detection system’. By sounding the alarm bell, it may perhaps even help to prevent future exits. Finally, the index allows modeling the effect that Britain’s exit will have on the exit propensities of other member states, thereby providing an objective means to assess the risk of contagion effects.