An economic moat provides a gauge of a company's competitive advantages and overall strength, and it is a highly valuable tool for investors of all levels.
Why Moats Matter by Heather Brilliant and Elizabeth Collins: http://www.amazon.com/Why-Moats-Matter-Morningstar-Investing/dp/1118760239/
For all Morningstar videos: http://www.morningstar.com/cover/videocenter.aspx
