Read the fine print on any published stock chart. It will always say something like:
Past Performance is not an Indication of Future Performance.
If you look at average gains since 1939 you can see that the stock market only outperformed bond market by a slight margin.
Did you read the article and the link to the longer (origional) one on which Milton Friedman commented?
Of course, there's no such thing as a sure thing. Who would expect that (other than one of the DemocRAT party's constituants)? One could immediately write off any person as a nit-wit who would not add the prudent caveat that the past isn't a guarantee of the future. Even in a horse race, "past performance" is an indicator of "future performance" barring any inforseen difficulties/problems.
Thanks for your comments.
Not only that, I have to question the author's arithmetic and use of statistics:
"Since 1871 in the U.S., all 40-year periods (there were 89)"
2001-1871=130
130 div 40 = 3 -- count 'em -- 3(!) statistically independent samples.