中文摘要：

不同于既有研究关注政府规模扩张的影响因素和经济效率，本文考察了我国政府规模扩张的社会福利效应，有两个重要发现：第一，非线性。本文使用2000-2012年省级面板数据和Hansen-TM方法实证发现，2000年以来，我国省级政府规模与财政分权、转移支付、经济增长的交互作用对社会福利具有非线性影响，分别表现出N型、倒U型和N型。第二，地异性。各省份由于财政分权程度、转移支付力度和人均收入水平差异，上述非线性机制和政府规模影响社会福利的门槛效应具有典型的地区差异。在“供给侧结构性改革”背景下，为防范政府规模扩张对社会福利增进由“初始的正效应”转向“最终的负效应”，本文提出了相应的政策矫正建议。

英文摘要：

Unlike existing studies focus on factors and economic efficiency of government expansion, this paper studies the welfare effect of government＇s size. There are two important findings： （1） By using provincial panel data in 2000-2012 and the Hansen＇s threshold model, we find the mutual effect of China＇s fiscal decentralization, transfer payments, economic growth with government＇s size on social welfare are nonlinear, which respectively exhibit remarkable ＂N-type＂, ＂inverted Le＇ and ＂N-type＂ nonlinear mechanism. （2） These mechanisms and threshold effect of social welfare have regional differences. This paper puts forward useful corrective policy recommendations in the con- text of supply-side structural reforms, to prevent social welfare of expansion of government＇s size from ＂initial positive effect＂ to ＂ultimate negative effect＂.