http://www.usatoday.com/money/perfi/columnist/waggon/story/2012-01-05/stocks-bonds-diversification/52395986/1

Great column from John Waggoner in USA Today. The headline is a reference to the fact that over the last 1yr, 10yr, 20yr and 30ys periods, bonds (long term treasuries, mainly) have had higher total returns (with dividends all reinvested) than large-cap US stocks (mainly the S&P 500).

Some takeaways:

1. the selection of stocks is not necessarily a great representation
2. the bond performance is very unlikely to be repeated since it all covers a period during which bond yields were dropping – from almost 14% in 1981 to about 3% today (and bond prices go up when their yields go down, so a lot of that long term performance was due to this)