中文摘要：

地方政府的政策性补贴，扭曲了要素市场价格，压低投资成本，形成产能过剩．并成为中国经济波动的主要影响因素。为了更好刻画这一现象，本文将产能利用率作为厂商最优选择的内生变量加入实际商业周期（RBC）模型，在动态随机一般均衡框架下讨论外生的随机’中击、政策性补贴冲击对经济主要变量的影响。对引入产能利用率的RBC模型进行数值模拟．发现其可以较好解释中国经济的现实波动；利用这一模型的脉冲响应函数发现。政策性补贴加大会更快形成产能过剩，从而对主要宏观经济变量产生影响；方差分解的分析进一步验证了这一结论：政策性补贴的变化和外生的随机冲击对产能过剩和宏观波动影响不相上下．都构成产能利用率和中国经济波动的主要原因。其中在投资增量的波动中．政策性补贴的影响更是成为最主要因素。缓解中国经济波动中产能过剩顽疾的根本途径，还是应该着力改善地方政府的激励机制，减少其进行政策性补贴的冲动，理顺要素市场价格。

英文摘要：

By distorting the factor prices and driving down the investment costs of producers, local governments＇ subsidies lead to overcapacity and thus become the main cause of economic fluctuation. In order to demonstrate the important role overcapacity and government subsidy play in the economic fluctuation of China, this paper takes capacity utilization as an endogenous variable of the optimal choice of enterprise, incorporates it into the RBC model and discusses the effect of exogenous stochastic shock and government subsidy shock on major economic variables under the DSGE framework. Numeric simulation shows that the modified RBC model can explain the economic fluctuation well. The iwpulse response functions of the model prove that the increase of government subsidy would induce faster overcapacity and thus impact major macro-economic features. Variance decomposition analysis confirms this conclusion further by showing that the government subsidy changes and exogenous stochastic shocks both lead to overcapacity and economic fluctuation, and government subsidy becomes the major cause of the investment waves. Our study points out that the key point to solve the overcapacity problem in economic fluctuation of China is to reform the incentive mechanism of local government so as to avoid excessive government subsidy.