道理是这样的：消费者债务高企、人口增长下降和不平等的恶化削弱了消费需求、刺激了储蓄，而生产率和产出本身增长放缓抑制了投资。
The argument goes like this: high consumer debt, slowing population growth, and rising income inequality have weakened consumer demand and stimulated savings, while slowing growth in productivity and output itself has discouraged investment.