Journal of Economic Perspectives · 2026 · [{"name": "David Weil", "affiliation": ["Brown University"]}]
中文摘要
我评估持续低于更替水平的生育率对年龄调整后人均消费的影响。所评估的渠道包括：劳动年龄成年人向儿童和老年人的转移、劳动力增长率对所需资本投资的影响、政府债务的可持续性、人口规模与固定自然资源（包括清洁环境）的相互作用，以及人口规模对技术进步速度的影响。为将低生育率的影响与其他正在发生的人口变化区分开来，我使用了模拟模型，以及联合国和社会保障署（Social Security Administration）的预测——这些预测在保持其他因素不变的情况下改变生育率。我的主要发现是，低生育率的影响很可能为负，但幅度较小。此外，这一负面影响只有在经历较长的调整期之后才会出现。将生育率提升回更替水平将在数十年内降低生活水平。
Abstract
I assess the effect of continued sub-replacement fertility on age-adjusted consumption per capita. Channels assessed include transfers from working-age adults to children and the elderly, the effect of the labor force growth rate on required capital investment, sustainability of government debt, the interaction of population size with fixed natural resources (including a clean environment), and the effect of population size on the speed of technological progress. To isolate the effect of low fertility from other ongoing demographic changes, I use simulation models as well as projections from the United Nations and Social Security Administration that vary fertility rates while holding other factors constant. My main finding is that the impact of low fertility is likely to be negative but small. In addition, this negative impact arrives only after a long adjustment period. An increase in fertility back to the replacement rate would lower the standard of living for several decades.