Sam, good discussion and thanks for the mention. I separate debt into two camps: consumer and investment. Consumer debt is bad, but I do think that the prudent use of investment debt is good (or "productive", as you say). Note I consider buying a house to live in consumer debt, not investment debt (one common mistake that helps keep people poor). Investment real estate with positive cash flow is one prudent use of debt if done well. Student debt (in many cases), mortgage on your house, cars, credit cards, etc are all debt that will make you poor. Understanding the difference is critical.