Many investors, especially during earnings season, seem to focus on the income statement. How much revenue was there? How much net income was there? Yet that focus can be dangerous, because the balance sheet actually tells us a lot about how the company is doing, and what it's likely to be doing in the not-too-distant future. Today, I'll focus on two balance sheet line items, accounts receivable and inventories, and how they relate to sales.

In Thornton O'Glove's book Quality of Earnings, he calls the analysis of A/R and inventory growth relative to sales the "best method" to get ahead of Wall Street analysts:

One of these simple ploys -- the best method I have ever discovered to predict future downwards earnings revisions by Wall Street security analysts -- is a careful analysis of accounts receivables and inventories. Learn how to interpret these ... a larger than average accounts receivable situation, and/or a bloated inventory. When I see these, bells go off in my head.

If A/R goes up significantly faster than sales, then the company could be stuffing the channel, pulling sales in from the future. It can only do so for so long before customers get fed up and stop buying for a while. Then the company ends up missing revenue and earnings, and the stock price gets whacked.

Similarly, if inventory is rising significantly faster than sales, that could mean demand is slowing down, and a big inventory writedown might be coming. Alternately, sales will be hurt when the company uses large markdowns just to clear out inventory.

Note that I'm not talking about normal business-cycle stuff. Many retailers build up inventory prior to the holiday season in order to meet expected demand. That's normal. Instead, I'm looking for a big disconnect between the growth of sales and the growth of A/R or inventory. That's a potential sign of a risky investment, and it makes me dig a bit deeper to see what's going on.

Let's apply this to Pfizer (NYSE: PFE), the big pharmaceutical company. Here's what the company has reported for the last four-quarter period, and for the last two year-over-year periods. I've also included a couple of others for comparison's sake.

Metric

Pfizer

Merck (NYSE: MRK)

sanofi-aventis (NYSE: SNY)

Revenue growth, TTM

34.8%

67.3%

5.4%

A/R growth, TTM

34.1%

106.9%

19%

Inventory growth, TTM

90.5%

189.7%

19.8%

       

Revenue growth, year ago

(5.5%)

(3.8%)

3.9%

A/R growth, year ago

2%

(16.8%)

13.6%

Inventory growth, year ago

(6.4%)

(1.6%)

13.7%

       

Revenue growth, 2 years ago

0.8%

3.7%

(2.2%)

A/R growth, 2 years ago

7.9%

1.1%

(2.1%)

Inventory growth, 2 years ago

(7%)

24.5%

(4.4%)

Source: Capital IQ, a division of Standard & Poor's; TTM = trailing 12 months.

Normally, I'd be all over Pfizer -- and Merck, too -- for letting inventory grow by such a huge amount relative to sales. But in the case of these two companies, at least, this is an artifact of their big acquisitions which closed at the end of last year: Wyeth for Pfizer and Schering-Plough for Merck. That probably also explains the big jump in A/R that Merck saw over the past year. Sanofi also has gone through a couple of good-sized mergers over the past couple of years, namely Chattem and Zentiva, that likely accounted for the two years of growth in A/R and inventory relative to sales. Acquisitive industries, such as big pharma, can make analysis such as this somewhat difficult for investors, but years in which such mergers didn't happen will help give clues as to what "normal" should be. In that light, the three of them don't look too bad.

Pay attention to the balance sheet, plug a few numbers into a simple spreadsheet, and, according to O'Glove, you can get ahead of Wall Street. This easy analysis, along with a bit of thought, gives you the potential to save yourself the heartache of seeing your investment get sharply cut when a company reports a "surprisingly" disappointing quarter.

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Fool analyst Jim Mueller doesn't have a position in any company mentioned. He works with the Fool's Stock Advisor newsletter service. The Motley Fool is investors writing for investors.