The effect of the Euro on country versus industry portfolio diversification

We examine the relative benefits of industrial versus geographical diversification in the Euro zone before and after the introduction of the common currency. A priori, one may expect that increased stock market correlation would precipitate a move from geographical towards industrial diversification. We employ the empirical model of Heston and Rouwenhorst but show that adopting a panel data approach is a more efficient estimation method. We find evidence of a shift in factor importance; from country to industry. However, this is not exclusive to the Euro zone but is also present for non-EMU European countries. Therefore, fund managers should pursue industrial rather than geographical diversification strategies.