一、引言投资、消费和出口是经济增长的“三驾马车”。根据凯恩斯主义,在经济衰退时期,出口减少,政府应该增加投资、减少税收,通过乘数效应来带动社会总需求的增加。财政政策决定了政府支出,而政府支出的资金来源除税收和借债外,主要体现 I. Introduction Investment, consumption and export are the “Troika” for economic growth. According to Keynesianism, during the economic downturn, exports have been reduced and the government should increase its investment and tax revenue to bring about an increase in aggregate social demand through the multiplier effect. Fiscal policy determines the government expenditure, and the source of funding for government spending is mainly reflected in taxes and borrowings