We don't have to speculate on this stuff, or base it on academic research from books: market P/E is easy to look up. Lo and behold it fluctuates dramatically.

We don't have to speculate on this stuff, or base it on academic research from books: market P/E is easy to look up. Lo and behold it fluctuates dramatically. Same with stock returns. Averaging 7% doesn't mean you get that return annually, or ever for that matter.