If you can borrow money at X% and put it towards a productive use that generates Y% returns, then it is worthwhile to do so when X < Y. The government can curre

If you can borrow money at X% and put it towards a productive use that generates Y% returns, then it is worthwhile to do so when X < Y. The government can currently borrow money at around 1-3% interest [0], depending on the length of the term. Presumably, the return you can generate from borrowed money diminishes as you borrow more money, so "good debt" is some amount of money that you have borrowed that allows you to be more productive and pays for its own interest, in a sense. But borrowing even more than that would start to become less useful, and drag down your overall return. [0] https://www.bloomberg.com/markets/rates-bonds/government-bonds/us https://www.bloomberg.com/markets/rates-bonds/government-bon...