In 1986,
Gary P. Brinson, L. Randolph Hood, and
SEI's Gilbert L. Beebower (BHB) published a study about asset allocation of 91 large
pension funds measured from 1974 to 1983. They replaced the pension funds' stock, bond, and cash selections with corresponding market indexes. The indexed quarterly return was found to be higher than the pension plan's actual quarterly return. The two quarterly return series' linear
correlation was measured at 96.7%, with
shared variance of 93.6%. A 1991 follow-up study by
Brinson, Singer, and Beebower measured variance of 91.5%. The conclusion of the study was that replacing active choices with simple asset classes worked just as well as, if not even better than, professional pension managers. Also, a small number of asset classes was sufficient for financial planning. Financial advisors often pointed to this study to support the idea that asset allocation is more important than all other concerns, which the BHB study is incorrectly thought to have lumped together as "
market timing" but was actually policy selection. One problem with the
Brinson study was that the cost factor in the two return series was not clearly discussed. However, in response to a letter to the editor, Hood noted that the returns series were gross of management fees. In 1997, William Jahnke initiated a debate on this topic, attacking the BHB study in a paper titled "The Asset Allocation Hoax". The Jahnke discussion appeared in the
Journal of Financial Planning as an opinion piece, not a peer reviewed article. Jahnke's main criticism, still undisputed, was that BHB's use of quarterly data dampens the impact of compounding slight portfolio disparities over time, relative to the benchmark. One could compound 2% and 2.15% quarterly over 20 years and see the sizable difference in cumulative return. However, the difference is still 15 basis points (hundredths of a percent) per quarter; the difference is one of perception, not fact. In 2000,
Ibbotson and Kaplan used five asset classes in their study "Does Asset Allocation Policy Explain 40, 90, or 100 Percent of Performance?". The asset classes included were large-cap US stock, small-cap US stock, non-US stock, US bonds, and cash. Ibbotson and Kaplan examined the 10-year return of 94 US balanced
mutual funds versus the corresponding indexed returns. This time, after properly adjusting for the cost of running
index funds, the actual returns again failed to beat index returns. The linear correlation between monthly index return series and the actual monthly actual return series was measured at 90.2%, with shared variance of 81.4%. Ibbotson concluded 1) that asset allocation explained 40% of the variation of returns across funds, and 2) that it explained virtually 100% of the level of fund returns.
Gary Brinson has expressed his general agreement with the Ibbotson-Kaplan conclusions. In both studies, it is misleading to make statements such as "asset allocation explains 93.6% of investment return". Even "asset allocation explains 93.6% of quarterly performance variance" leaves much to be desired, because the shared variance could be from pension funds' operating structure. Bekkers, Doeswijk and Lam (2009) investigate the diversification benefits for a portfolio by distinguishing ten different investment categories simultaneously in a mean-variance analysis as well as a
market portfolio approach. The results suggest that real estate, commodities, and high yield add the most value to the traditional asset mix of stocks, bonds, and cash. A study with such broad coverage of asset classes has not been conducted before, not in the context of determining capital market expectations and performing a
mean-variance analysis, neither in assessing the global market portfolio. Doeswijk, Lam and Swinkels (2014) argue that the portfolio of the average investor contains important information for strategic asset allocation purposes. This portfolio shows the relative value of all assets according to the market crowd, which one could interpret as a benchmark or the
optimal portfolio for the average investor. The authors determine the market values of equities, private equity, real estate, high yield bonds, emerging debt, non-government bonds, government bonds, inflation linked bonds, commodities, and hedge funds. For this range of assets, they estimate the invested global market portfolio for the period 1990 to 2012. For the main asset categories equities, real estate, non-government bonds, and government bonds they extend the period to 1959 until 2012. Doeswijk, Lam and Swinkels (2019) show that the global market portfolio realizes a compounded real return of 4.45% per year with a standard deviation of 11.2% from 1960 until 2017. In the inflationary period from 1960 to 1979, the compounded real return of the global market portfolio is 3.24% per year, while this is 6.01% per year in the disinflationary period from 1980 to 2017. The average return during recessions was -1.96% per year, versus 7.72% per year during expansions. The reward for the average investor over the period 1960 to 2017 is a compounded return of 3.39% points above the risk-less rate earned by savers.
Performance indicators McGuigan described an examination of funds that were in the top quartile of performance during 1983 to 1993. During the second measurement period of 1993 to 2003, only 28.57% of the funds remained in the top quartile. 33.33% of the funds dropped to the second quartile. The rest of the funds dropped to the third or fourth quartile. In fact, low cost was a more reliable indicator of performance.
Bogle noted that an examination of five-year performance data of large-cap blend funds revealed that the lowest cost quartile funds had the best performance, and the highest cost quartile funds had the worst performance. ==Return versus risk trade-off==