In his latest for Nasdaq.com, Validea CEO John Reese looks at the “economic moat” concept that helps guide Warren Buffett’s investment approach.

“Identifying companies with economic moats may seem like a subjective process, and to a certain extent it is,” Reese says. “But there are fundamental indicators that can be signs that a company has a moat. My Buffett-inspired Guru Strategy, which is based on the approach Buffett used to build his empire, views a lengthy history of a high return on equity as a sign that a company has an economic moat — the 10-year average ROE should be at least 15%, and the ROE should not be below 12% in any of those 10 years.”

Reese looks at 5 stocks that get high scores from his guru based strategies, and which Morningstar analysts find to have economic moats. Among them: PetSmart, which gets high marks from his Buffett- and Peter Lynch-based models.