Stock market’s return will grow at the same rate as the U.S. economy.
Might there be hope, after all, for the U.S. stock market’s return over the next decade? I ask as a follow up tomy column earlier this monthin which I concluded that even under optimistic assumptions, the S&P 500SPX,+0.51%over the next 10 years is unlikely to produce an annualized total real return greater than the low single-digits.
My argument was that the stock market will not be able to count on the three pillars that have propped it up over the past decade — increasing valuations, profit margins and more buybacks than new shares issued (net buybacks).
Some readers responded that I had overlooked an escape hatch which would enable the market to produce decent returns: corporate revenues can grow faster than the overall U.S. economy. To the extent this is so, then the stock market does not need any of those three pillars to do well.
This escape hatch appears to have solid evidence behind it. Consider a recent note to clients from Jonathan Golub, chief U.S. equity strategist and head of quantitative research at Credit Suisse. He reported that, according to an econometric model he constructed based on S&P 500 sales and GDP since 2000, “every 1% upside in nominal GDP drives 2½–3% improvement in revenues.”
If so, this certainly would be good for stock investors. It would mean that even without increasing valuations, profit margins or net buybacks, the stock market could significantly outperform the overall economy.
Unfortunately, this argument is too good to be true. I analyzed S&P 500 sales back to the early 1970s (courtesy of data from Ned Davis Research), and found almost a 1:1 correlation between sales growth and GDP growth.
This is entirely what we should expect, according to Robert Arnott, chairman and founder of Research Affiliates. In an email, he said that “aggregate sales should offer a pretty clean 1:1 relationship to GDP. Any other ratio makes no sense on a sustained basis.”
How then did Golub come up with such a different answer? My hunch is that it traces to how he measured sales. In an email, Golub’s colleague Manish Bangard, an equity strategist at Credit Suisse, explained that they focused on sales per share. But, as Arnott points out, this per-share number reflects the impact of net buybacks. So the high sales-to-GDP ratio that Golub reports is not a pure measure of how sales growth relates to GDP. (I did not receive a response to my requests for additional comment.)
Investment implication
The implication is that we should not expect the U.S. stock market over the next decade to grow faster than the economy. It may in fact grow much more slowly if P/E ratios or profit margins regress even partway to their historical mean, or if net buybacks turn out to be negative (as they’ve been for most of U.S. history).
But even if P/E ratios and profit margins stay constant between now and 2031 and there are no net buybacks, the lesson of history is that the U.S. market will grow no faster than the economy.
Consider what that means. TheCongressional Budget Office is projectingthat real GDP from 2022 through 2031 will grow at a 1.8% annualized rate. Even that may be optimistic, because the CBO projects no recession between now and then.
The bottom line: The stock market has its work cut out to produce even a fraction of the past decade’s fabulous return.