中国公共资本存量的再估计及其应用——动态一般均衡的视角

Re-estimation of China's Public Capital Stock and Its Application:A Dynamic General Equilibrium Perspective

在宏观经济研究中,公共资本存量是讨论政府支出弹性和乘数效应的基础数据。本文采用动态随机一般均衡模型,对不同形式调整成本的公共资本存量模型进行甄别,选出与中国实际经济最为契合的公共资本积累模型。通过"贝叶斯"方法,本文测算出中国公共资本的年折旧率为9.28%。根据选择的积累模型和折旧率,本文估计出全国及31个省份1978—2013年的公共资本存量。根据估算的结果,本文进一步讨论了公共资本的投资效率、区域间的公共资本差异及其最优性。研究发现:大部分省份公共资本的实际水平远高于产出弹性;公共资本的边际效率低于1,表明目前的政府投资水平是过度且低效的。

Employing a Dynamic Stochastic General Equilibrium Model,we compare different accumulating models of public capital with various adjustment cost and chooses the best one which fits Chinese datum well.Using the Bayesian method,we estimate that China＇s annual depreciation rate of public capital is 9.28%.We also estimate the whole country＇s public capital stock and the sub-national public capital stock during 1978—2013 with selected accumulation model and estimated depreciation rate.We then investigate the investment efficiency of public capital,the difference of public capital stock among sub-national governments,and its optimality.We find that the actual level of public capital in most provinces is much higher than its output elasticity,and the marginal efficiency of public capital is lower than 1,which indicates that the current governments＇ investment level is excessive and inefficient.