Deglobalization and the value of geographic diversification: evidence from Brexit
Authors: Tunyi Abongeh A. , Hussain Tanveer , Areneke Geofry 
Published: August 2023

PurposeThis paper aims to explore the value of geographic diversification in the context of deglobalization, drawing evidence from a quasi-natural experiment – the Brexit referendum that took place on 23 June 2016 in the UK.Design/methodology/approachThis study applies an event study methodology to estimate the impact of the Brexit vote on a cross-section of firms with varying levels of geographic diversification – undiversified UK firms, UK firms with significant operations in the European Union (EU) and globally diversified UK firms. This study deploys a Heckman two-stage regression approach to address sample selection bias.FindingsThis study finds that undiversified UK firms experienced negative cumulative abnormal returns (CARs) around the Brexit referendum. The value of UK firms with majority sales within the UK declined by 0.9 percentage points, on average, in the three days centred on the Brexit referendum. In contrast, UK firms that are globally diversified, with the majority of sales within the EU are unaffected, while diversified firms in the rest of the world generated positive CARs of 1.8 percentage points over the same period. These results are robust to firm characteristics, selection bias and alternative measures of CARs and diversification.Research limitations/implicationsThis study is subject to some limitations that open avenues for future work. There are a few available proxies of diversification and further work on developing other proxies is much needed. Further work may also examine the long-term impact of diversification on UK firms. This study considered Brexit as a quasi-natural experiment, and this study could be applied to other deglobalization events like COVID-19 and can enhance the generalizability of diversification strategy in the deglobalized world. Findings may stimulate future work to explore how another form of diversification – product diversification has affected firm returns around Brexit. Finally, this study has focused on the UK as its base case. It may be interesting to corroborate the findings by exploring the impact of Brexit on European firms, who hitherto Brexit, had some operations in the UK.Practical implicationsThis work offers some insights for policymakers and regulators around the impact of deglobalization on local firms. Findings suggest that these trends significantly negatively impact the most vulnerable firms (smaller firms with less global reach), while their larger counterparts with significant global reach might be insulated. This finding is important for determining the nature of support needed by different firms in times of deglobalization. The work also offers insights to managers of firms operating in countries where there are real prospects of deglobalization. Specifically, the work highlights the importance of geographic diversification when free movement of goods, services and people is restricted.Originality/valueThis study shows that a certain group of globally diversified firms earned significantly higher returns from the prospect of the UK leaving the EU, thereby highlighting the value of geographic diversification in a time of deglobalization.