Low price/earnings ratios are usually easy to find, even when the broad stock market seems expensive. For example, the S&P 500 index has climbed more than 30% in three months and now trades at 22 times trailing earnings, well above stocks 137-year average trailing P/E of 15. Still, one out of every eight index members has a P/E in single digits.

The task for investors, of course, is culling companies that seem under-appreciated from ones that deserve their piddling valuations. Often, a single-digit P/E means a company s earnings are expected to decline. Not all declines are equal, though. Some suggest long-term decay. Others are a temporary product of swings in consumer spending or raw materials prices.

Shares of companies that trade cheaply because of expected, temporary earnings stumbles might be just the thing for investors who worry that the broad market is priced for disappointment. Earnings underlying the S&P 500 are expected to grow 9% this year, even though they shrank by 39% in the first quarter. The index s price of about 17 times the 2009 forecasts suggests investors think reported growth will top the estimate, even though earnings last quarter fell short of forecasts by 24%. By contrast, for the humbly priced stocks to follow, a certain amount of anticipated disappointment is already priced in.

Chevron (CVX) earnings are expected to plunge this year but rebound sharply next year. My sympathies to the analysts who must try to assign precise numbers to such forecasts. Last summer crude peaked at more than $145 a barrel. Just before Christmastime it fell below $35. Now it s over $70 again. Better, perhaps, to focus on the dividend yield, which stands at 3.7%, versus about 2.3% for the broad market.

Carnival (CCL), the cruise line, seems perfectly emblematic of the sort of pricey frolicking the middle class can do without during a recession. The stock is accordingly about half its price of two years ago. Profits are indeed expected to fall 27% in Carnival s fiscal year ending Nov. 30, but in its past two quarterly reports the company topped estimates by double-digit percentages. Perhaps the outlook is gloomier than the reality. One downside: Management scrapped the dividend late last year.

Archer Daniels-Midland (ADM) buys, stores, processes and ships crops. Over the long term, its usefulness to a hungry planet seems assured. In the short term, its profits can swing with the frenzy of a futures pit. Last quarter the company missed earnings forecasts by 30%. The quarter before it beat by 33%. The stock is nine times forecast earnings for its current fiscal year ending June 30, but 12 times next year s lower forecast. Still, the higher of the two numbers seems plenty reasonable compared with the broad stock market. Shares pay 2%.

Below are listed these and two other stocks with single-digit P/Es.