We construct and parameterize an overlapping generations model for an open economy with individuals who differ in innate ability. Key endogenous variables are hours worked, investment in human and physical capital, and per capita growth. The model replicates important data in Belgium since 1960 remarkably well. Simulating it, we observe that behavioral adjustments by households and firms contribute to reverse the negative arithmetical effect of future demographic change on per capita growth. Individuals work and study more. However, with unchanged policies, there remains a net negative effect on annual per capita growth of almost 0.3%-points on average in the next 25 years. This is mainly due to adverse consequences of reduced fertility and a declining working-age population on (the return to) physical capital investment. Model projections also point to rising income inequality induced by demographic change. Differences in the capacity of individuals to respond to increasing life expectancy by investing in education, and by saving, are key.

中文翻译：

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开放经济中人口变化对宏观经济和分配的影响——以比利时为例

我们构建并参数化了一个开放经济的重叠世代模型，其中个体的先天能力不同。关键的内生变量是工作时间、人力和物质资本投资以及人均增长。该模型很好地复制了比利时自 1960 年以来的重要数据。模拟它，我们观察到家庭和公司的行为调整有助于扭转未来人口变化对人均增长的负算术影响。个人工作和学习更多。然而，在政策不变的情况下，未来 25 年对人均年增长率的净负面影响仍然接近 0.3 个百分点。这主要是由于生育率下降和劳动年龄人口减少对实物资本投资（回报）的不利影响。模型预测还指出人口变化导致收入不平等加剧。个人通过投资教育和储蓄来应对预期寿命延长的能力差异是关键。