I've shown that valuation matters numerous times over the years when it comes to long-term equity returns (see here, here, and here for some of my favorite examples). The below post uses the same concept in that it compares valuation (i.e. yields) with forward returns, but in this version we compare the relative performance of equities vs. bonds.
While I refuse to state that returns will be anywhere near this 9.5%, by almost all measures stocks appear cheap on a relative basis to Treasury bonds. Unless earnings collapse back to a "normal" percent of the overall economic pie abruptly (definitely possible, but in my view not likely) or the economic pie contracts abruptly, stocks are going to outperform bonds over the next ten years.