[M]argins have been rising smartly–faster than Greenspan can ever recall. His only explanation: productivity… Greenspan argues that the U.S. is undergoing a productivity revolution not seen since early this century… In the longer term, he’s betting that as the world moves into the 21st century and the New Economy takes root, more of the old economic rules will fall apart.
- From “Alan Greenspan’s Brave New World,” Business Week, July 13, 1997
As you may know, GMO and Hussman take the position that stocks are expensive, citing a variety of indicators and arguing that profit margins should “mean revert” from record highs. On the other side, market bulls dispute the indicators and propose that fat margins are no big deal – they might just remain at record highs indefinitely.
“High margins reflect a long-term structural change, not a short-term cyclical one,” according to one account of a popular position. Also: “It’s a mistake to think that margins will revert to a long-term mean just for the sake of reverting to a mean.”
The message seems to be that mean reversion is for losers. This is a new era, or it’s a new economy, or whatever. I’m paraphrasing, but the story sounds a lot like the capital letter New Economy of the late 1990s. There’s even a technology angle once again, along with huge confidence in monetary policy and recession-free growth. Above all, there’s a notion that the world might be different.
Needless to say, the new, new economy story comes with plenty of red flags. But let’s not dismiss it just because it didn’t pan out the last time around. If we’re not buying the story, we should at least have a clear rationale and not just assume mean reversion “for the sake of reverting to a mean,” as noted above. I’ll take a shot at providing such a rationale. Or, as Brad Katsuyama might say: “Let’s do this.”