Abstract:  Labor supply is an important source of economic growth．In this paper，we use the factorization method to quantify the contribution of labour supply in China's economic growth by decomposing the labor supply factor into the population size，the proportion of working-age population，and the labor participation rate factors．We put them all into the classic Cobb-Douglas production function．Based on the theoretical model derivation，this paper analyzes the time series data from 1978 to 2015．The results show that labor supply has a significant contribution to China's economic growth in a long term．Its impact and contribution are less significant than the fixed assets，but much greater than the human cap- ital．The main contribution of China's economic growth comes from the input of material capital rather than the labor supply．All of the three variables representing the scale of labor supply have significant effects on economic growth in the same direction，but the magnitude of the effects varies．The order of the contribution and elasticity of the three factors to the total economic output are the total population，the proportion of the working-age population，and the labor participation rate．Finally， in recent years the decrease of the proportion of working-age population does suppress China's economic growth，but this negative impact is to some extent offset by the increase in the size of the total population．

Keywords:  Labor Supply, Population Size, Proportion of the Work-age Population, Labor Participation Rate, Economic Growth

摘要： 劳动力供给是经济增长的重要源泉之一。文章将劳动力供给因素分解为总人口规模、 劳动年龄人口比重和劳动参与率的乘积，并纳入柯布—道格拉斯生产函数中，在理论模型推导的基础上， 利用中国1978 ～2015 年的时间序列数据进行分析，发现:( 1) 长期以来我国劳动力供给因素对经济增长 有显著正向作用，其影响程度和对经济增长的贡献度明显小于物质资本，但远高于人力资本的影响和贡 献;( 2) 构成劳动力供给规模的3 个组成要素均对我国经济增长产生显著的同方向影响，三者的产出弹 性和贡献度按照大小依次为:总人口规模、劳动年龄人口比重和劳动参与率;( 3) 近年来劳动年龄人口比 重下降对经济增长产生抑制作用，但在一定程度上被总人口规模增加的正向作用所抵消。

关键词: 劳动力供给, 人口规模, 劳动年龄人口比重, 劳动参与率, 经济增长