THE IMPLICATIONS OF BREXIT REFERENDUM ON THE LONG-RUN RELATIONSHIP BETWEEN THE EURO AND POUND STERLING: RESIDUAL AUGMENTED LEAST SQUARE BASED EVIDENCE
Authors: Usta Ahmet , Kutlu Melih 
Published: September 2023

Purpose- The aim of this study is to investigate the economic effects of Brexit from the viewpoint of exchange rates. This research studies the impact of Brexit on long-run relationship between euro and pound sterling. It is crucial to assess how Britain’s vote to leave the European Union affects long-term relationship between euro and pound sterling because such action may have significant financial and economic implications on both economies (Diez et al., 2019; Korus & Celebi, 2019; Nagarakatte & Natchimuthu, 2022).
Methodology- This study utilizes daily trade-weighted real effective exchange rate indices for euro (EUR) and pound sterling (GBP) over the period of January 1, 2013 to December 31, 2019 to investigate the impact of Brexit referendum took place on June 23, 2016 on the long-run relationship between euro and pound sterling. We exclude European sovereign debt crisis and pandemic periods. As stated previously, this study considers June 23, 2016 as the reference to assess the impact of Brexit on the relationship between currencies. Therefore, our analysis involves three periods including full sample period, pre- and post-Brexit. Empirical investigation relies on residual augmented least squares (RALS) based approach. Due to Im & Schmidt (2008), Im, Lee, & Tieslau (2014), and Lee, Lee, & Im (2015), we use RALS-based unit root test and cointegration analysis. While traditional tests (augmented Dickey-Fuller unit root and Engle-Granger cointegration) assume that error terms are normally distributed, which is a very strict assumption, RALS-based tests relax that condition. We also conduct Granger (non-) causality test proposed by Toda & Yamamoto (1995) to investigate the direction(s) of possible causalities between euro and pound sterling for each period.
Findings- RALS based unit root test results suggest that the time series of exchange rates contain unit root for full sample, pre- and post-Brexit periods. The only exception is the time series of sterling pound is I (0) in post-Brexit period. According to the unit root test results, we can conclude that foreign exchange markets in both economies follow weak form efficiency for all sample periods. However, this is not valid for the sub sample where the time series of pound sterling is stationary at level, in post-Brexit. RALS based cointegration test results show that there is no cointegration between the time series of EUR and GBP. This general result is confirmed by both models, RALS ADL and RALS EG2. However, we observe a cointegrating relationship between two currencies in post-Brexit period when we treat GBP as the dependent variable. According to the Granger non-causality test results, we fail to reject null hypothesis and conclude that there is no causality running from EA to UK and vice versa for all sample periods. Test results reveal one exception. In the post-Brexit period, EUR Granger causes GBP implying that the past values of EUR are useful to forecast GBP.
Conclusion- Interdependence of world economies is increasing as the financial integration is deepening. Key political, economic, and financial developments in the global world should be followed and assessed. Such developments at home or abroad may influence the prospects. Therefore, it is crucial to assess the outcomes of Brexit-like events that clearly have impact on economic and financial environment to take necessary actions.

Keywords: Exchange rates, Brexit referendum, Euro, Pound Sterling, RALS Cointegration Test
JEL Codes: C32, F31, G15