While many investors and advisors believe that asset allocation and diversification failed during the markets and economic crisis of 2008-2009, Roger Ibbotson begs to differ. In a keynote speech delivered during the Morningstar Ibbotson Asset Allocation conference on March 4, 2010, in Orlando, the founder of Ibbotson Associates and the current chairman and CIO of Zebra Capital argued for a more nuanced understanding of the benefits of asset allocation and diversification. Asking himself that very question–Do asset allocation and diversification still work?–Ibbotson said that “in newspaper-speak, the short answer is yes.”
Using the data to back up his argument, Ibbotson noted that in 2008, about 25% of U.S. listed stocks lost at least 75% of their value, “but only four of the more than 6,600 unlevered open-end mutual funds available for sale lost more than 75% in 2008–so diversification does work!”
In his speech and in a two-part article he is co-authoring in the CFA Institute’s March/April 2010 Financial Analysts Journal (along with Morningstar/Ibbotson’s James Xiong, Tom Idzorek, and Peng Chen), Ibbotson revisits the Brinson-Hood-Bebower contention that asset allocation accounts for 90% of a portfolio’s return, arguing instead that the sources of variation of returns from a portfolio are around 75% from the overall market, with the remainder about equally split from portfolio-specific asset allocation policies and from individual securities in the portfolio, along with the timing of trades, and fees.
Ibbotson argues that there are five drivers of portfolio performance over the long term–what he calls the “Big Five”: