Here is a graph we do in my office of the Shiller 10-year normalized price/earnings ratio. Remember that this is an aggregate valuation; there is a lot of variation within the market. But stocks are not cheap. (That doesn't mean they won't beat bonds over the next decade.) You'll need to click on the image to get a good look.
And here's Robert Shiller
himself, talking about the data series, bringing the numbers to life. Note that the date of the Shiller interview is from Sept. 27 of last year, when the S&P 500 closed at 1,175. It closed today at 1,351.
To be clear, this is my own graph, not his, but we use his numbers.