关键词: 经济不确定性, 财政政策有效性, 市场信心, 信贷约束

Abstract: This paper estimates Chinas economic uncertainty index at the national level and of 31 provinces （cities and regions），and analyzes the impact of economic uncertainty on business cycle fluctuations and the effectiveness of fiscal policy The research findings are as follows：（1） economic uncertainty at the national level and economic uncertainty at the provincial level are both important factors affecting the fluctuation of provincial business cycle；（2） during periods of higher economic uncertainty，fiscal policy has a higher multiplier effect and can serve as a policy tool to compensate for the weakening of monetary policy effects；（3） enhancing market confidence and easing credit constraints are important ways for fiscal policies to exert the “stabilizing growth” effect，and fiscal policies mainly affect economic growth through investment channels Therefore，proactive fiscal policies are an effective tool for addressing the impact of uncertainty

Key words: economic uncertainty, fiscal policy effectiveness, market confidence, credit constraints