Correlations and spillovers among three euro rates: evidence using realised variance

This paper uses three euro exchange rates – the US dollar, sterling and yen – to test for the presence of volatility spillovers and time-varying correlations using the realised variance approach, which has significant advantages over the multivariate-GARCH methodology. Our results suggest that the three currencies do exhibit some degree of volatility spillover and hence commonality in the driving force behind volatility movement. With regard to the nature of time-variation within the correlation coefficients, there is substantial evidence that correlations are time-varying but that the strength of correlation coefficients has not increased over the sample period. Furthermore, there is evidence that correlations themselves are predictable and interrelated. These results support the view that the three rates do exhibit interrelationships, commonality and time-varying correlation, factors that are important to portfolio managers. This latter point is illustrated by using the realised variances and covariances to determine portfolio weights, the portfolio variance of which is lower than constructing portfolios using (rolling) unconditional values.