Mary Buffett.
by Mary Buffett — Buffettology · Warren Buffett investment methodology interpretation
Author and speaker who co-wrote Buffettology and The New Buffettology, translating Warren Buffett's investment approach for individual investors. A former daughter-in-law of Warren Buffett, she spent years observing his analytical methods firsthand.
About Mary Buffett
Mary Buffett is a business author and speaker best known for co-authoring a series of books that interpret and explain Warren Buffett's investment methodology for general audiences. She was married to Warren Buffett's son Peter Buffett from 1981 to 1993, during which time she had direct exposure to Warren Buffett's approach to business analysis and long-term investing.
Her first book, Buffettology (1997), co-authored with David Clark, introduced the concept of "Business Perspective Investing" — a framework that translates Buffett's publicly observable investment decisions into a set of learnable principles. The book emphasizes seeking companies with durable competitive advantages (which Buffett calls "economic moats"), predictable earnings, and management that allocates capital efficiently.
The New Buffettology (2002) updated the framework with additional case studies and refinements. Subsequent books in the series — including The Tao of Warren Buffett (2006) and Warren Buffett and the Interpretation of Financial Statements (2008) — continued to extend the accessible treatment of Buffett's methodology.
It is worth noting that Mary Buffett's work represents her interpretation of publicly observable Buffett behavior and statements, not an official or authorized account. Warren Buffett has not endorsed her books. Readers seeking Buffett's own words will find his annual shareholder letters — freely available online — to be the primary source.