I’m a little surprised this doesn’t include the classic results of the people throwing darts. It’s been done innumerable times and over periods of a year or decades. Get a group of people and have them throw darts at the share price pages of the newspapers of your starting date. Measure the returns of those shares picked in such a manner at your closing date. A very surprisingly large percentage of the time these portfolios do better than any of the managed funds who are, one assumes, using some method they consider better than random chance to invest.

But the shorter Nick Cohen article of the title?

Prediction is very difficult, especially about the future.

(Sorry, forgotten the source of that one.)