I enjoyed the article and the additional analysis on some of the underlying drivers of Shiller CAPE multiples. The article doesn't spend a lot of time critiquing Shiller CAPE. Mostly, is supports the concept and the value of looking at starting valuations. By either measure, they argue that valuations are at the top decile of this historical range and the future returns are likely to be disappointing to most investors.

But they do show that the dot com bubble was a more extreme outlier than Shiller CAPE might indicate because index changes don't show up in the Shiller PE as traditionally calculated until the new components have time to get incorporated into the history. So today, the market valuations are high, and the CC CAPE is higher than Shiller CAPE, indicating some exuberance, but not nearly the extreme that the dot com period had.