In 2000, General Electric posted its 100th consecutive quarter of growth in continuing operations. That's 25 years. Raise your hand if that sounds just a bit suspicious. Whatever business you're in, that feat just isn't possible unless your company's managing its reported earnings.

According to a 1998 survey, 78% of CFOs attending a given conference said they'd been asked to "cast financial results in a better light" without running afoul of GAAP. Half said they'd done it. Nearly half said they'd been asked to misrepresent their company's numbers, and 38% admitted they'd done so. Another survey at a different conference found that more than half of the CFOs attending had been asked to juice their numbers, and 17% had agreed to do so.

It's easy to understand why companies succumb to the incredible pressure to make it look like they've met or beaten targets or Wall Street expectations. Consistent growth is a feather in any CEO's cap, and a rising stock price often increases many executives' compensation, especially from stock options. But when companies stray from merely managing their numbers within GAAP into outright fudging them -- Enron, Sunbeam, we're looking at you here -- they can ruin themselves and their shareholders.

How can we spot suspicious earnings patterns soon enough to save ourselves? We can track how closely a company meets earnings expectations, monitor its frequency of year-over-year growth, and compare those stats to numbers from a few competitors, which should be affected similarly by changes in the business cycle. Any company that lands eerily close to earnings-per-share (EPS) expectations, and grows earnings year-over-year with unusual reliability, should raise a yellow flag and invite us to look closer.

Here's a look at what National Oilwell Varco (NYSE: NOV), the oil services company, has done over the past few years. I've also included a couple of other businesses playing in the same space for comparison.

Company

Reported EPS Within $0.02 of Estimates?

How Close to Estimates, on Average

How Often It Reported Growth

National Oilwell Varco

9 times in last 26 quarters.

$0.06

18 times in last 22 quarters.

Schlumberger (NYSE: SLB)

13 times in last 26 quarters.

$0.02

15 times in last 22 quarters.

Halliburton (NYSE: HAL)

16 times in last 26 quarters.

$0.03

17 times in last 22 quarters.

Source: www.earnings.com and author calculation. Difference in number of quarters counted due to data source.

In my view, there's not much to worry about for National Oilwell. Barely one-third of the time has it come real close to estimates, and, on average, it's been further away than our range of concern. The steady growth is most likely due to the growth in the oil drilling business over the last several years. Of the three, the only one that might raise a yellow flag is Halliburton, and that would only be because it had come with a couple of pennies more often than not. More like a pale yellow flag.

Note that I'm not concentrating on managing estimates here -- though management does that, too. However, if a management team always seems to deliver on estimates time and time again, you should probably dig a bit deeper, to see whether its interpretation of GAAP is getting a bit too fast and loose.

Investors crave consistency. That's one reason why its string of reliable results spurred GE's stock price to rise so much in the 1980s and 1990s. But the real world isn't consistent, and Foolish investors should account for that. If a company's results seem too steady to be true, Fools should proceed with caution.

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Fool analyst Jim Mueller is a beneficial owner of General Electric and owns shares of Schlumberger, but doesn't have a position in any other company mentioned. He works with the Stock Advisor newsletter service. The Fool is all about investors writing for investors.