Bloomberg Opinion columnist Barry Ritholtz interviews Ray Dalio, who is founder, co-chairman and co-chief investment officer of the world’s largest hedge fund, Bridgewater Associates. Dalio has been a global macro investor for more than 45 years, having started Bridgewater out of a two-bedroom apartment in New York City in 1975. He is known for the practical yet unconventional theory of economics he spells out in his video series "How the Economic Machine Works," and is the author of the New York Times bestseller "Principles: Life and Work." His newest book, "Principles for Navigating Big Debt Crises," was published this month.