中国人口年龄结构与储蓄率关系研究

摘要

摘要

作为宏观经济学中的一个重要问题，储蓄问题涉及到整个经济体系的各个层面；而储蓄问题本身就是一个十分值得重视的研究内容，尤其是在中国当前居民储蓄率一直处于较高水平以及老龄化程度日益严重的情况下，研究人口年龄结构对居民储蓄率的影响具有十分重要的现实意义。

本文以一个包含少年、中青年以及老年三代的叠代模型为理论框架，首先得到了在稳定人口年龄结构下的稳定状态劳动人口人均资本存量以及居民总储蓄率，进而分析了人口年龄结构变动对稳定状态劳动人口人均资本存量以及居民总储蓄率的影响。得到以下结论：

第一，少儿抚养比与老年抚养比增加都会使当代劳动人口承担更重的消费负担，从而都会使居民总储蓄率下降；

第二，同样幅度的变动，老年抚养比的增加比少儿抚养比的增加引起的居民总储蓄率下降更大。原因在于老年抚养比还会影响劳动人口人均资本存量，亦影响居民总储蓄水平。换句话说，在劳动人口不变的情况下，老年人口数量上升将使得稳定状态下的资本存量和居民总储蓄下降，进而影响产出水平。而少儿抚养比则不存在这一效应。

随后，本文构建协整模型以检验居民储蓄率、少儿抚养比与老年抚养比之间的长期协整关系。检验结果显示，少儿抚养比和老年抚养比的变动可以解释居民储蓄率变动的91%；少儿抚养比上升一个百分点，居民储蓄率将下降0.79个百分点，而老年抚养比上升一个百分点，居民储蓄率则将下降0.98个百分点。实证检验结果较好地支持了理论模型结论。

根据上述理论模型和实证结果，在当前人口年龄结构下，高储蓄率的现状在短期内不会改变；同时，由于储蓄最终将转变为实物资本投资、人力资本投资、技术开发投入和外汇储备，鉴于当前中国投资-储蓄转化效率不高，人力资本投资与技术开发投入水平亦相对较低，外汇储备也将在一段时间内保持高位。但是，一旦老龄化程度加深，人口年龄结构改变将冲击中国的高储蓄率。如果在此之前未能实现经济结构转型，那么我国的外汇储备也将缩水。也就是说在相关政策基本不变的情况下，中国的储蓄率会在保持高位一段时间后开始下降，

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摘要

外汇储备也将经历同样的变动，那么人民币汇率在未来一段时间内将受到较大的升值压力，随后则可能贬值。为缓解当前的升值压力，同时降低未来经济的波动性，经济结构的调整迫在眉睫。

本文的创新之处在于所构建的模型能够较好地刻画当前中国人口年龄结构与居民储蓄率的关系，并且区分了少儿抚养比与老年抚养比对居民储蓄率的不同影响作用，且得到了较好了实证支持。

关键词：叠代模型居民储蓄率少儿抚养比老年抚养比

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Abstract

Abstract

As an important issue of macroeconomics, saving would influence all the aspects of the economy, and plenty of papers have focused on this significant issue. Saving issue, to be more specific, the relationship between population age structure and household saving rate must be paid enough attention to, especially for China as its saving rate has been extremely high for a long time while the aging problem has begun to strike the country in the meantime.

In an Overlapping Generation Model including the young generation, the middle-age generation and the old generation, the thesis firstly obtains the expression of the steady state capital stock per capita and household saving in the steady age structure, and therefore analyses the impact of the change in the age structure on the steady state capital stock per capita and household saving. The conclusions are as follows:

First, the increase in the youth dependency ratio and the old age dependency ratio both mean that the present working age generation will carry more economic burden, thus evoke the decrease in the household saving rate;

Second, with the same change in the youth dependency ratio and the old age dependency ratio, the later has a larger impact on the household ratio. This is due to the fact that only the old-age dependency ratio influences the steady state capital stock per capita and household saving. In the condition of stable working age population, a larger old age population will make the capital stock per capita, the amount of household saving and therefore the output fall, while the youth dependency ratio has no similar effect.

In the following part, the thesis examines the cointegration relationship among the household saving rate, young dependency and old age dependency. The result shows that 91% of the change in household saving rate could be explained by the change of the youth dependency ratio and the old age dependency ratio; with 1 percent increase in the youth dependency ratio and the old age dependency ratio, the

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