关键词: 政府债务 , 世代交叠模型 , 动态无效率

Abstract: Based on a three sectors overlapping generations model with endogenous growth mechanism, this paper discusses longterm equilibrium of the economy in which government borrows finance for public investment. At the same time, we study Chinas equilibrium government debt scale and its influence factors through numerical simulation method. The following conclusions are found: firstly, there is a positive equilibrium government debt to output ratio in the economy system under certain conditions, which is affected definitely by the parameters of public investment to output ratio, proportion of debt financing in public investment and private capital output elasticity. Secondly, the equilibrium government debt ratio cant rise unlimitedly, as the economy would lose equilibrium, government debt to output ratio will continue to rise, and the fiscal policy will be unsustainable, when the mentioned parameters exceed the specific critical values. Thirdly, when the private capital output elasticity is relatively low, the high equilibrium government debt can lead to dynamic inefficiency of the economy. Additionally, the numerical simulation shows that, based on the different assumptions, currently the equilibrium government debt to output ratios in China are higher than the actual debt ratio, which provides a favorable basis for the future implementation of the expansionary fiscal policy.   

Key words: government debt , overlapping generations model , dynamic inefficient