morph366

U.S. and BRIC World Market Share

Interesting as your graph is, what it shows is a convergence in market capitalizations which reflects global investor flows rather than a true picture of the underlying soundness/prospects of the businesses in each geographical region.
Correlations across all assets classes tend towards unity in times of crisis but this may be more a reflection of poor liquidity and risk aversion than a statement about the P/E outlooks etc. for the emerging markets versus the more mature ones.