Best Asset Allocation For Retirees?

A December 2009 Financial Planning magazine article "Disappearing Act" from one of my favorite authors Dr. Craig L. Israelsen illustrates with back-testing how a Multi-Asset Portfolio equally weighted between large-cap domestic stocks, small-cap domestic stocks, foreign stocks, real estate, commodities, bonds, and cash has the best chance of surviving a 25-year retirement period at the highest withdrawal rates. The typical recommendation is to annually use 4-5% of your retirement nest egg with a 3% cost-of-living adjustment (COLA) increase per year, yet the Multi-Asset Portfolio survives a 7.5% withdrawal rate and almost survives a whopping 10% withdrawal rate! I think even a better portfolio construction would be to increase exposure to more foreign assets across all categories, particularly Emerging Markets. Also, the S&P GSCI used for the Commodities category is very skewed towards energy. I'd suggest using DJP or RJI for more diversity.