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Commentary

Are Bonds Going to Outperform Stocks Over the Long Run?

Some argue that investors should allocate entirely to bonds, which they think will beat stocks over the long run. We're skeptical.

Given the poor performance of stocks over the past year and the past decade, there has been ample discussion about the relative performance of stocks versus bonds. Some even argue that investors should allocate entirely to bonds, not only because bonds are the safer investments, but because they believe bonds will outperform stocks over the long run. In other words, if bonds can deliver higher returns with less risk, why bother with stocks?

Table 1 below shows the performance of the S&P 500 and Intermediate-Term and Long-Term Government Bonds over various time periods. Not only have the average annual stock returns been poor over the last 10 years, but relative to bonds, stock returns look mediocre over the last 20, 30, and even 40 years.

By looking at the returns over the last 40 years, the argument that bonds might outperform stocks looks to be valid. But one should view this with skepticism. First, note that over the 20-, 30-, and 40-year periods, stocks actually performed quite well, even if some bond categories did better. Over the very long term, it is no longer a contest.

 Table 1: Compound Annualized Total Returns (%) Ending March 2009

 

S&P 500

IA SBBI Int-Term
Gov't Bond
IIA SBBI Long-Term
Gov't Bond
1 Year: Starting April 2008 -38.09 6.24 14.32
5 Year: Starting April 2004 -4.77 5.17 7.79
10 Year: Starting April 1999 -3.00 6.31 8.20
20 Year: Starting April 1989 7.42 7.39 9.61
30 Year: Starting April 1979 10.30 8.57 9.93
40 Year: Starting April 1969 8.70 8.03 8.79
Jan 1926-March 2009 9.44 5.40 5.60
Source: Ibbotson

Chart 1* gives the results of the capital market returns over the last 83 years. During this longer period, stocks easily beat bonds.

Table 2** looks at a longer history of U.S. stocks. The returns on the stock market have been consistently high over almost two centuries. The returns over the last 40 years are roughly comparable to the more distant returns.

Long-term history provides two major insights:

1. Stocks have outperformed bonds.
2. Stock returns are far more volatile than bond returns, thus more risky. Given the additional amount of risk, it is not surprising that stocks don't outperform bonds every period--even over extended periods of time.

 

Stocks vs. Bonds in the Future
How likely are stocks to outperform bonds going forward? To try to figure out the future, let us look in more detail at what happened during the last 40 years.

Despite the substantial decline in yields over the last 40 years, Chart 2 shows that the bulk of the bond returns come from the income return portion, or yield. On average, the bond income return from coupon payments was more than 7%. Capital gains caused by the yield decline made up the additional return.

Today, yields are much lower. Table 3 presents the current bond yield information. As of the end of the first quarter of 2009, the Long-Term Government Bond yield was 3.55% and the Intermediate-Term Government Bond yield was only 1.68%. For bonds to continue to enjoy the same amount of capital gains over the next 40 years, a rough estimation would put the yield into negative territory, especially for Intermediate-Term Government Bonds. This is simply impossible, because it implies that investors would be willing to lend their money to a borrower and pay the borrower an interest rate. Over the last 40 years, bond investors have enjoyed abundant returns because of a high-yield environment followed by a steady decline in yields.

  Table 3: Bond Yield %

 

April 1969 March 2009 Change
IA SBBI US LT Government Yield USD 5.93 3.55 Declined 2.38
IA SBBI US IT Government Yield USD 6.36 1.68 Declined 4.68
Source: Ibbotson

To analyze which asset class is more likely to outperform going forward, let's take a deeper look at the historical data and the current market environment. We analyze each component of returns going forward for stocks and bonds as follows:

Bond returns = current yield + capital gain
Stock return = current yield + earning growth + P/E changes

First, given the current low-yield environment, it would be almost impossible for bonds to generate the same amount of capital gains as they did in the past. In fact, a reasonable estimate might be that there will be no more capital gains going forward, since yields may be at least as likely to rise as to fall. (Some would even argue that bond yields would likely increase over time, thus producing capital losses for bonds.) If there were no future fall in yields, all of the return would have to come from the coupon return. That means the total returns for bond investments would likely be between 2% to 3%.

For stocks, the dividend yield in 2008 for the S&P 500 was 1.92%. If stocks produce more than 2% in capital gains per year on average, they will likely beat bonds. Stocks' capital gains can be decomposed into nominal earnings growth and changes in the P/E ratio***. Historically, U.S. long-term nominal earnings growth has been roughly 5%, which is comparable to the nominal GDP growth. If we assume the market valuation level (operating P/E of S&P 500) stays at the same level over the next 40 years, then we would have an equity return of around 7%. Even if we forecasted a decline in the valuation level, the 10-year average P/E level would need to fall from just about 20 to below five to get equity returns around 3%.

Conclusions
Bonds not only have outperformed stocks by a large margin over the past year because of the financial crisis, but also roughly matched stocks over the past 40 years. This begs the question, will bonds continue to outperform?

Upon closer examination, we show that stock returns over the last 40 years were virtually in line with the long-term historical average. On the other hand, bond returns were not only much higher than their historical averages, but also higher than their current yields. This high bond return is due to higher interest rates in the 1970s and a subsequent declining interest rate environment. This scenario for bonds is very unlikely to repeat in the future, given today's low interest rate environment. Investors hoping bonds will outperform in the coming years will likely be disappointed.

Stocks tend to outperform bonds over time, but are much more risky, even over longer periods. Bonds can outperform stocks over a long period, but investors need almost perfect timing to get in and out of the market to realize such returns. We believe the right strategy is to follow a disciplined asset allocation policy that considers the return and risk tradeoffs by taking advantage of the diversification benefits between stocks and bonds over time.

As Warren Buffett wrote in his 2009 annual shareholder letter: "When the financial history of this decade is written, it will surely speak of the Internet bubble of the late 1990s and the housing bubble of the early 2000s. But the U.S. Treasury bond bubble of late 2008 may be regarded as almost equally extraordinary."

* Past performance is no guarantee of future results. Hypothetical value of $1 invested at the beginning of 1926. Assumes reinvestment of income and no transaction costs or taxes. This is for illustrative purposes only and not indicative of any investment. An investment cannot be made directly in an index.

** Stock returns from 1825-1925 are from the article authored by William N. Goetzmann, Roger Ibbotson, and Liang Peng, "A New Historical Database for the NYSE 1815 to 1925: Performance and Predictability," Journal Financial Markets, December 2000.

*** We can decompose stock capital gains into earnings growth and P/E changes. For detailed information on the formula, please refer to Roger Ibbotson and Peng Chen. "Long-Run Stock Returns: Participating in the Real Economy." Financial Analysts Journal, 59 (January/February 2003), pp. 88-98.

Disclosures
The performance data shown represents past performance. Past performance does not guarantee future results. The above commentary is for informational purposes only and should not be viewed as an offer to buy or sell a particular security. The data and/or information noted are from what we believe to be reliable sources; however, Ibbotson has no control over the means or methods used to collect the data/information and therefore cannot guarantee their accuracy or completeness. The opinions and estimates noted herein are accurate as of a certain date and are subject to change. The indexes referenced are unmanaged and cannot be invested in directly.

This commentary may contain forward-looking statements that reflect our current expectations or forecasts of future events. Forward-looking statements are inherently subject to, among other things, risks, uncertainties and assumptions that could cause actual events, results, performance or prospects to differ materiality from those expressed in, or implied by, these forward-looking statements. The forward-looking information contained in this commentary is as of the date of this report and subject to change. There should not be an expectation that such information will in all circumstances be updated, supplemented or revised whether as a result of new information, changing circumstances, future events or otherwise.