Are US stocks priced for earnings growth that hasn't materialized yet?
Core argument: The reason is that the ten-year average of earnings increases only gradually because rapidly rising current earnings are averaged together.
When it comes to valuing the stock market, one critique of CAPE is that it can send misleading signals during periods when earnings are growing rapidly and stock prices are rising alongside them. The reason is that the ten-year average of earnings increases only gradually because rapidly rising current earnings are averaged together with older earnings that may have grown much more slowly. This causes CAPE to rise. This is essentially the situation today. Companies exposed to the AI boom have experienced extraordinary earnings growth, and their stock prices have followed suit. But the ten-year average of earnings has not increased nearly as quickly, leaving CAPE at a high level. It is important to note that Shiller was fully aware of this discrepancy between a slowly moving average and rapidly rising current earnings. In fact, he designed CAPE with exactly this in mind. His argument was that earnings are highly volatile, so a smoothed measure of earnings provides a better estimate of the ‘fair’ value of stocks than current earnings, which can be distorted by temporary booms and busts.

