Long-Run International Diversification

The evidence for international diversification as a means to curtail portfolio risk relies predominantly on short-run data. In this paper, we examine the extent to which the risk reduction benefits of international investment hold in the long-run. Employing a multi-horizon non-parametric filter, we develop a long-run correlation estimator and exploit this to decompose the long-run inter-market relationship into short-run components. We observe raised correlations between international equity indices in the long-run. Investigating the economic significance for investors, we find the long-run benefits of international diversification to be attenuated. Increasing long-run correlation is modeled as a function of short-run data accounting for characteristics pervasive in financial time series. This indicates that perceived risk reduction benefits may be overstated using short-run data