Abstract: The demographic dividend is a key driver of China's rapid economic growth since the reform and opening-up in the late 1970s. However, few studies have systematically covered its full cycle—investment, profit, and repayment periods. Five paths of the demographic dividend to promote economic growth are deduced through mathematical reasoning, and the relationship between population policy, the demographic dividend, and long-term economic growth is further examined. A new economic growth accounting method is constructed with the idea of counterfactual simulation, which realizes the path decomposition and overall sum of the economic growth effect of the demographic dividend, and then compares and analyzes the time sequence, path and effect intensity of the demographic dividend under different policy scenarios. The study finds that population policy has a significant impact on long-term economic growth in the dimensions of economic aggregate, growth trend and mode. The channel through which population policy affects economic growth is the demographic dividend, and it exerts its influence by changing the timing of the formation of the demographic dividend, the path of its action, and the strength of its effect. The economic growth effect of population policy is long-term and persistent, and the economic growth paths under different policies may converge in the short run but still diverge in the long run.

Keywords: Population Policy, Demographic Dividend, Economic Growth, Counterfactual Simulation

摘要： 人口红利是改革开放后中国经济快速增长的重要原因，但目前尚未看到涵盖人口红利投资期、获利期与偿还期全周期的研究。基于数理推导得出的人口红利促进经济增长的5条路径，考察人口政策、人口红利与长期经济增长之间的关系。借鉴反事实模拟思路构建一种新的经济增长核算方法，实现对人口红利经济增长效应的路径分解与加总，进而对比分析不同政策情境下人口红利的形成时段、作用路径与效应强度。研究发现:人口政策在经济体量、增长趋势与增长模式等维度上对长期经济增长产生显著影响;人口政策影响经济增长的渠道是人口红利，它通过改变人口红利的形成时段、作用路径、效应强度来产生影响;人口政策的经济增长效应具有长期性和持续性，不同政策下的经济增长路径即便短期内未展现出显著差异，长期仍可能分化。

关键词: 人口政策, 人口红利, 经济增长, 反事实模拟