Vanguard and others have put a lot of emphasis on bonds diversification using international bonds in recent years, while the Bogleheads community mostly shrugged. This article studies the effect of such diversification through backtesting techniques, looking at both regular International bonds and Emerging Market bonds. We’ll take a close look by studying monthly returns to better analyze the volatility and correlation properties of various portfolios. Then we’ll perform a similar study about diversification of equities with domestic, global or international real estate funds.