The article explains that when people face risks and limits on borrowing money, their tendency to save more can actually increase as their income grows. This means that as people earn more, they save a higher percentage of their income, even without high interest rates. For example, if income grows from 1% to 10%, savings can increase from 5% to 25% without changes in interest rates. This pattern has been seen in countries like Japan and China, where people saved more as their incomes rose over time.