March 2, 2009, 2:44 pm
Stocks Finally Start Looking Affordable
By David Leonhardt
Updated at market close.
At long last, stocks are beginning to look cheap.
With today’s declines, the long-term price-earnings ratio of the Standard & Poor 500-stock index is down to about 12.3. Over the past century, this ratio has averaged about 16. So relative to corporate profits, the stock market now appears to be undervalued by about 30 percent.
For months now, we have been following the stock market’s decline here at Economix and arguing that the market was not as inexpensive as many others were arguing. Our case: Despite the enormous fall in stocks, the long-term p-e ratio — that is, the ratio based on the past 10 years of corporate earnings — was still roughly at its historical average.
But the declines over the last few weeks are starting to change the picture. I crunched some of the historical stock data kept by Robert Shiller, author of “Irrational Exuberance,” and it offers some reason for optimism. When the p-e has been between 12 and 13 over the last 125 years or so, stocks have doubled over the next decade, on average. (Adjusting for inflation, they have risen almost 50 percent.)
Over all, there is pretty direct correlation between the p-e ratio and future long-term returns. For example, when the ratio has been 15 to 20, stocks have risen only about 50 percent over the next decade. When the ratio has been above 25, stocks haven’t risen much at all.
So does this mean stocks are finished falling? No.
In the other two great bear markets of the past century, in the 1930s and the 1980s, the p-e ratio ultimately dropped to about 6 or 7. To get to that level now, the S&P 500 would have to drop below 400, from the current 701, and the Dow Jones industrial average would need to be below 4,000. So stocks may well continue to fall. They may even still fall a fair amount.
But long-term investors — and that describes most of us — should start to feel perfectly fine about buying stocks. Investors who bought in the late 1930s or late 1970s, when the p-e was also around 12, had a rough ride. But they did quite nicely if they held their stocks for a decade or more.
