From the linked WSJ article: "All of this might be enough to put investors off stocks entirely, until they consider the long-term alternatives. Measured over the 1978-2008 period, rather than over just one decade, stock performance in real-real terms actually is better than that of just about any other major investment class, Mr. Thornburg found: 4.5% a year. Stocks' ability to keep up with inflation over the very long haul may be their best selling point.
In real-real terms, stocks did better over that period than municipal bonds (2.5% a year), long-term government bonds (2% a year) and corporate bonds (0.2% a year). Real-real home prices were unchanged over those 30 years. Both short-term government bonds and commodities suffered losses. (Mr. Thornburg has experience investing in all these areas, although his mortgage affiliate went bust in last year's housing collapse.)"