Whether you're a beginning investor or a near-retiree, the importance of purchasing stocks that pay dividends cannot be overstated. Not only do companies that have quarterly or annual payouts provide you with a steady stream of income, they also have the potential for capital appreciation. Simply put, dividend stocks can you give your portfolio what almost no other investment can -- both income and growth.

At The Motley Fool, we're avid fans of dividends -- and not just because we like that steady stream of cash. Studies have shown that from 1972 to 2006, stocks in the S&P 500 that don't pay dividends have earned an average annual return of 4.1%; dividend stocks, however, have averaged a whopping 10.1% per year. That is an incredible difference -- one you'd be crazy not to take advantage of!

But investing in dividends can be dangerous; companies can cut, slash, or suspend dividends at any time, often without notice. Fortunately, there are several warnings signs that may alert you, and these red flags could be the crucial factor in determining whether a company is likely to continue paying its dividend. Today, let's drill beneath the surface and check out Coca-Cola (NYSE: KO).

What's on the surface?
Coca-Cola, which operates in the soft-drinks industry, currently pays a dividend of 3.2%. That's certainly nothing to sneeze at, as the average dividend payer in the S&P 500, in 2009, sported a yield of 2%.

But what's more important than the dividend itself is Coca-Cola's ability to keep that cash rolling. The first thing to look at is the company's reported dividends versus its reported earnings. If you happen to see dividend payments that are growing faster than earnings per share, it may be an initial signal that something just isn't right. Check out the graph below for details of the past five years:


Clearly, there doesn't seem to be a problem here. Coca-Cola has been able to boost its earnings at an adequate pace and keep its dividends in check at the same time.

The more secure, the better
One of the most common metrics that investors use to judge the safety of a dividend is the payout ratio. This number tells you what percentage of net income is paid out to investors in the form of a dividend. Normally, anything above 50% is cause to look a bit further. According to the most recent data, Coca-Cola's payout ratio is 53%. While this payout ratio isn't necessarily outrageous, it would serve us well to dig a bit deeper. Let's take a look at Coca-Cola's free cash flow to see if there are enough greenbacks to support that 53% payout ratio.

Free cash flow -- the cash left over after subtracting out capital expenditures -- is used by firms to make acquisitions, develop new products, and, of course, pay dividends! We can use a simple metric called the cash flow coverage ratio, which is cash per share divided by dividends per share. Normally, anything above 1.2 should make you feel comfortable; anything less, and you may have a problem on your hands. Coca-Cola's coverage ratio is 1.76, which is more than enough cash on hand to keep pumping out that 3.2% yield. Barring any unforeseen circumstances, there really shouldn't be any major problems moving forward.

Either way, it's always beneficial to compare an investment with its most immediate competitors, so in the chart below, I've included the above metrics with that of Coca-Cola's closest competitors and other high-performing consumer-goods companies. In addition, I've included the five-year dividend growth rate, which is also a very important indicator. If Coca-Cola can illustrate that it's grown dividends over the past five years, there's a good chance that it will continue to put shareholders first in the future. Check out how Coca-Cola stacks up below:

Company

Dividend

Yield

Payout

Ratio

Coverage Ratio

5-Year Compounded
Dividend Growth Rate

Coca-Cola

3.2%

53%

1.76

9.9%

PepsiCo (NYSE: PEP)

2.9%

46%

1.85

14.0%

Philip Morris International

4.5%

62%

1.89

N/A

Kraft Foods (NYSE: KFT)

3.9%

46%

1.32

7.2%

Coca-Cola Enterprises (NYSE: CCE)

1.3%

21%

4.45

16.3%

Dr Pepper Snapple Group (NYSE: DPS)

2.7%

14%

11.17

N/A

Source: Capital IQ.

The Foolish bottom line
Only you can decide what numbers you're comfortable with in the end; sometimes a higher yield and a higher reward mean additional risk. However, in this situation, Coca-Cola's payout ratio seems to be above the peer average, which means if you're a prudent investor, you may want to look elsewhere for the most secure payment possible. Not that the company is in jeopardy of slashing its dividend, but you could possibly get a higher yield with a better coverage ratio elsewhere. The bottom line, however, is to make sure that with anything -- whether it be a dividend, a share repurchase, or an ordinary earnings report -- you do your own due diligence. Looking at all of the numbers in the best context possible is just the best place to start.