How Much of Historical Stock Returns Is Due To P/E Ratio Expansion?

According to Multpl.com, the P/E ratio of the S&P 500 is now 35, and the dividend yield is only 1.3%. The all-time low dividend yield was 1.11% back in August 2020. Even if you consider stock buybacks, the earnings yield is less than 3%! That means if corporations all distributed every penny of their profits as dividends, it still wouldn’t be higher than 3%. Before we go any further, I’m not advocating market timing, as people were saying that the S&P 500 was “overvalued” back in 2015 when the P/E ratio was 25 and the dividend yield was 2%. Nobody truly knows what will happen to prices in the short-term.

Even if the P/E ratio seems a lot higher now than the historical average, what has that actually meant? The Morningstar article How Much Has the Market Benefited from Investor Optimism? examines how much of the historical return of the S&P 500 from 1976 through March 2021 was from P/E expansion.

In January 1976, the P/E ratio was only 11.8. In March 2021, the P/E ratio was 31.5. That seems like a huge difference, and over that 45-year time period, it did add 2.2% to the overall historical average annual return. But we also got 3% from earning growth, and another 2.75% from dividends, for a total return of ~8% above inflation. 8% real return!

In a way, this is somewhat comforting, as if you look at the long-term, a shrinking P/E ratio won’t completely destroy your retirement by itself. Instead of adding 2%, it might subtract 2%.

Looking ahead, if you assume a generous 4% from earnings growth, 0% from a constant P/E ratio, and 1.3% from dividends, that’s roughly a 5% future real return. But if the P/E ratio goes back even partly back to historical averages, that will be closer to a 4% real return. The problem is that bonds are giving us 0% real return at best, so I’m sticking with owning productive businesses.

The numbers on my brokerage statements keep going up so perhaps I shouldn’t complain, but I sure hope the earnings start to catch up to the prices soon (as some predict). I like the idea of the P/E ratio going down due to higher earnings rather than lower prices!