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，- I -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- II -AbstractAbstractAs 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- III -Abstracthousehold saving rate decreases 0.79 and 0.98 percent respectively. The empirical result accords with the OLG model.The above result is of major and immediate significance. Based on the theoretical model and the empirical result, household saving rate will remain high in the present age structure; as the saving finally transfers to real capital investment, human capital investment, R&D and foreign exchange reserve, and with the poor efficiency of the transformation from saving to real investment, and the low level of human capital investment and R&D, China’s foreign exchange reserve would keep in high level in the short run. However, once the aging problem is severe enough, the change in age structure will significantly strike China’s high saving rate. If proper measures haven’t been taken to promote economic restructuring before that happen, China’s foreign exchange reserve would shrink dramatically. It would begin to fall after a period of high level, experiencing the similar trend of the household saving rate, thus the RMB exchange rate might depreciate after suffering a long time under appreciation pressure. So it is suggested that the economic restructuring is extremely urgent in order to relieve the present appreciation pressure, and to reduce the severity of economic fluctuation.The highlight of the thesis is that the theoretical model explains well of the relationship between the present population age structure and household saving rate of China, and furthermore differentiates the impacts of youth dependency ratio and old age dependency ratio on household saving rate, which is supported by the empirical results.Key Words: OLG Model Household Saving Rate Youth Dependency Ratio Old Age Dependency Ratio- IV -目录目录第一章引言 (1)第一节研究背景与意义 (1)第二节研究方法与论文结构安排 (3)第二章文献综述及理论基础 (4)第一节生命周期理论及其理论拓展 (4)第二节实证检验研究 (6)第三节理论基础 (9)第三章理论模型 (11)第一节稳定人口年龄结构下的均衡解 (11)一、模型构建 (11)二、消费者最优化决策 (12)三、厂商最优化决策 (13)四、市场均衡条件 (14)五、稳定状态条件 (14)第二节人口年龄结构变动对稳定状态的影响 (15)一、人口年龄结构变动对稳定状态劳动人口人均资本的影响 (15)二、人口年龄结构变动对稳定状态下居民储蓄率的影响 (15)第四章实证检验 (18)第一节样本描述与变量选取 (18)一、居民储蓄率 (18)二、人口年龄结构 (19)三、经济增长速度 (20)四、平稳性检验 (21)- V -目录第二节协整检验 (22)一、包含居民储蓄率与少儿抚养比、老年抚养比和人均GDP增长率的协整检验22二、包含居民储蓄率与少儿抚养比和人均GDP增长率的协整检验 (23)三、包含居民储蓄率与老年抚养比和人均GDP增长率的协整检验 (23)四、包含居民储蓄率与少儿抚养比和老年抚养比的协整检验 (24)第三节格兰杰因果检验 (25)一、居民储蓄率变动与少儿抚养比变动的格兰杰因果检验 (25)二、居民储蓄率变动与老年抚养比变动的格兰杰因果检验 (26)三、居民储蓄率变动与人均GDP增长率的格兰杰因果检验 (26)第四节实证检验结论及居民储蓄率变化趋势预测 (26)第五章结论与政策建议 (29)参考文献 (35)附录 (37)致谢 (45)个人简历 (46)- VI -第一章引言第一章引言第一节研究背景与意义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。