Investing in dividend stocks is a great way to build long-term wealth. Studies have shown that dividend-paying stocks outperform non-dividend-paying ones, and a dividend reinvestment plan, or DRIP, which allows you to use dividends to buy more of the stock paying it, is an excellent way to grow your portfolio without putting in any more of your hard-earned cash.

Of course, it's even better if you can count on those stocks to keep paying you -- and even increase those dividends as you get older. Below, our analysts explain why they think W.P. Carey (NYSE:WPC)International Paper (NYSE:IP), and Wal-Mart Stores (NYSE:WMT) are top choices for dividend stocks that will pay you for the rest of your life. 

Several rolled dollar bills that look taller from left to right

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Steady income from real estate

Matt DiLallo (W.P. Carey): Real estate investment trust (REIT) W.P. Carey has been investing in commercial real estate for more than 40 years. While the company has only been public since 1998 -- and didn't become a REIT until 2012 -- it has consistently paid dividends to investors each year. In fact, it has increased its payout every single year since going public.

That steady stream of income should continue flowing to investors in the years ahead. Driving that view is W.P. Carey's focus on owning net lease properties, which generate consistent cash flow because the tenant pays most of the operating expenses. Currently, the company owns 890 properties around the world, which have a weighted average remaining lease term of nine and a half years and a current occupancy rate of 99.8%. Those factors provide the company with clear visibility on future cash flow. 

Further supporting W.P. Carey's ability to keep sending cash to investors is its conservative financial profile. For starters, the 5.7%-yielding dividend only consumes about 75% of its cash flow. Further, the company has an excellent balance sheet backed by a low leverage ratio of 46% total debt-to-total assets, which is well below the 60% allowable under its current agreements with lenders. Those two factors give W.P. Carey the financial flexibility to continue building and buying more properties, which should push cash flow higher, making it even more likely that this REIT will keep paying investors for years to come.

The best dividend stocks are the most boring

Maxx Chatsko (International Paper): If you're looking for a dividend stock that will keep paying you indefinitely, then you should find a company that is large, mature, oozes with cash flow, sells products that its customers couldn't replace very easily, and is so boring you would overlook it otherwise. International Paper checks off every one of those boxes.

While the heydey of the American pulp and paper industry has long since passed, paper products are still an essential part of modern life. That's especially true for corrugated packaging products, which most people simply refer to as cardboard boxes. The incredible growth of online shopping is expected to result in record demand for corrugated packaging by 2020 and then some.

Good news: International Paper is the lowest cost manufacturer of corrugated products. It's also one of the largest. The company can produce 13 million metric tons year from 166 container plants in the United States, manufacturing capacity that allowed its industrial packaging division to turn in $14.2 billion in sales and $1.65 billion in operating profits in 2016. The segment has also been a free cash flow machine: The pulp and paper leader averaged $1.8 billion in free cash flow from 2012 to 2016.

That's all great news for dividend investors, especially considering management has pledged to return 40% to 50% of free cash flow to shareholders every year through dividends and share repurchases. So far, so good: The annual dividend has increased from $1.05 per share at the end of 2011 to $1.90 per share this year. Look for the payout to continue rising. 

The biggest company in the world

Jeremy Bowman (Wal-Mart): With $486 billion in revenue last year, Wal-Mart is the biggest company in the world by sales. The retail behemoth has used its economies of scale, supply chain expertise, and reputation for low prices to carve out leading positions in the retail industry not just at home, but internationally as well, in countries like Mexico, Brazil, China, and the U.K.

Not surprisingly, Wal-Mart is also a reliable dividend payer. The retailer has increased its dividend payout every year for 43 years in a row, making it a Dividend Aristocrat, and the company's recent strategic moves including buying for $3.3 billion and rapidly expanding its online grocery pickup program make it well positioned to continue to thrive in the future.

As the stock has soared this year, the dividend yield has slipped to 2.1%, and recent annual dividend hikes have been modest at just a penny, or 2%, as Wal-Mart invests in e-commerce and improving stores. However, dividend growth could accelerate next year as profits are expected increase again after years of investments in higher wages and e-commerce.

Wal-Mart's payout ratio is below 50%, meaning it has plenty of room to raise its dividend payouts even if profit growth lags. However, the company is looking stronger than it has in a long time, and its defensive business model as a low-price operator means the stock can easily withstand a recession. I'd expect another 43 years of rising dividends from this retail giant.