The IMF Working Papers series is designed to make IMF staff research available to a wide audience. Almost 300 Working Papers are released each year, covering a wide range of theoretical and analytical topics, including balance of payments, monetary and fiscal issues, global liquidity, and national and international economic developments.
The degree of comovement across national stock markets has increased dramatically since the mid-1990s. This has overturned a stylized fact in the international portfolio diversification literature that diversifying across countries is more effective for risk reduction than diversifying across industries. We investigate if this rise in comovement is a permanent phenomenon driven by greater economic and financial integration, or a temporary effect associated with the recent stock market bubble. At the global level, our results point to the bubble. At a regional level, we find evidence of a significant rise in market integration within Europe, possibly a reflection of institutional changes such as the EMU.