We calibrate an overlapping-generations model with a rich demographic structure to observed and projected changes in U.S. population, family composition, life expectancy, and labor market activity. The model indicates that demographic factors associated with the post-war baby boom pushed up real interest rates and real gross domestic product (GDP) growth from 1960 to the 1980s. Since the 1980s, the model accounts for a little more than a 1-percentage-point decline in both real GDP growth and real interest rates—much of the permanent declines in those variables according to some estimates. Our model predicts GDP growth and interest rates will remain low by historical standards, consistent with a “new normal” for the U.S. economy.

我们校准了具有丰富人口结构的重叠世代模型，以观察和预测美国人口，家庭组成，预期寿命和劳动力市场活动的变化。该模型表明，从1960年到1980年代，与战后婴儿潮时期有关的人口因素推高了实际利率和实际国内生产总值（GDP）的增长。自1980年代以来，该模型在实际GDP增长率和实际利率方面都只下降了1个百分点以上，根据一些估计，这些变量的大部分永久下降。我们的模型预测，按照历史标准，GDP增长和利率将保持较低水平，与美国经济的“新常态”一致。