Jeremy Siegel has been a well-respected name on Wall Street for years. His Stocks for the Long Run is a sacred text for any long-term investor, and in 1999, he accurately predicted the Internet bubble. So when Siegel talks, it's a good idea to listen.

I recently finished his 2005 book, The Future for Investors. Siegel spends the first half of the book making crystal clear the two traits that, he argues, will always reward long-term, buy-and-hold investors.

  1. A difference between actual and expected earnings growth, and ...
  2. Dividends.

Earnings growth
Earnings growth is great, but if that growth is already priced into the stock, then the potential downside is far greater than the upside.

Some favorite picks among growth investors have this type of dangerous exposure. Shares of women's clothier lululemon athletica, cloud-computing leader, and movie-streamer extraordinaire Netflix all have P/E ratios at or above 50. Though these are all excellent companies that could very well keep on returning market-beating results to shareholders, there's extra risk involved here.

Instead of investing in these highfliers, Siegel preaches the importance of companies whose earnings growth will -- if ever so slightly -- outpace the expectations baked into the stock's price. The key metric for understanding how much growth is expected: price-to-earnings.

The stock I'm suggesting to you at the end of the article has a forward P/E of just 9.3, and its two-year earnings growth stands at 24% annually. Moving forward, analysts expect the company to increase earnings by 11% annually.

But first, the importance of dividends
Now, Siegel was looking at returns over the long-term horizon. Sure, capital gains will yield strong results in the short term, but there's nothing that'll supercharge your returns in the long run like dividends. By reinvesting all of your dividends, the magic of compounding takes over, accumulating more and more shares of a company at almost no cost to you.

The company I'm suggesting today is a dividend aristocrat, having increased its dividend in each of the past 25 years. It also has a five-year dividend growth rate of 21.4%.

As impressive as this is, the company has a payout ratio (the amount of earnings spent on dividends) of only 25%, meaning that it can easily continue to raise its dividend without trouble for the foreseeable future.

Tell me the name, already!
The company I'm referring to is supplemental-life insurer Aflac (NYSE: AFL). Everyone's favorite duck is poised to continue rewarding loyal long-term investors.

Though I tend to like the riskier stocks (see my disclosure below), I also own Aflac because I think it has a predictable business model, run by a solid management team. Diversifying is important, and Aflac will be a long-term winner that can provide stability in anyone's portfolio.

Want to read more about Aflac? Add it to My Watchlist, which will find all of our Foolish analysis on this stock.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.