Ray Dalio’s “Principles for Navigating Big Debt Crises” is the work of a self-taught economist and self-made billionaire. The first 70 pages of the book, in which the founder of Bridgewater Associates introduces his theory of debt cycles, have no citations. He apparently stands on the shoulders of nobody. Mr. Dalio’s education came on trading floors, not in classrooms. “Big Debt Crises” is his response to that challenge: a compilation of historical case studies presented as a trader would have experienced them in real time.

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