老龄化、人口迁移、金融杠杆与经济长周期

Population Aging,Migration,Financial Leverage and the Economic Long Swing

本文以房地产这一代表性的资本品为纽带,综合库兹涅兹"长周期"理论和城市层级体系理论,构建了中国"长周期"可计算一般均衡(CGE)模型。并以日本战后的人口数据和宏观经济数据为基础估计参数,模拟分析人口老龄化和人口迁移两大人口性因素对中国2015—2050年经济增长、城镇化和房地产价格的中长期影响。本文还引入金融杠杆和理性预期因素,探讨了杠杆率与经济增长、人口迁移及出生率的相互作用关系。研究发现,由于人口老龄化的影响,中国的经济增速在2021—2025年可能会出现台阶式下行,并触发房价下跌和"逆城镇化"。为此,必须注重"关键三率":(1)总和生育率,采取措施提高生育率在短期内和中长期都可以有效提高经济增速;(2)人口迁移率,提高人口迁移便利性有助于经济增长;(3)金融杠杆率,在确定长期杠杆率上限的基础上,短期内灵活运用杠杆工具有利于促进经济增长。只要风险可控,不宜过度压制杠杆率的自然上升。

This paper uses housing price as a linking factor and integrates the Kuznets ＂ Long Swing＂ in demographic economics and the hierarchical urban systems model in geoeconomics. We build a CGE model for China＇s Long Swing, and use demographic and c data of Japan to estimate the model, and then use it to analyze the long-term impact of population aging and migration on China＇s economic growth, urbanization and housing prices in 2015--2050. We also add financial leverage and rational expectation factors to the model, so as to study the linkage between financial leverage, economic growth and demographic polices. We find that the aging problem will cause a step-down of China＇s economic growth rate in 2021--2025, which will trigger off the slide of housing prices across the country, and cause the phenomenon of deurbanization. In order to maintain long-term sustainable growth, we must focus on the three key rates： First, the total fertility rate （TFR）. If the government adopts policies to raise the TFR, economic growth will be stimulated both in the short-term and in the long-term. Second, the migration rate. Easier migration polices will help upgrade the economy and thus increase the growth rate. Third, the financial leverage ratio. Flexible adjustment of the leverage ratio with a long-term ceiling in mind will help stabilize economic growth. In addition, excessive limitation on the naturally rising leverage ratio will hurt economic growth.