保经济增长下限与非线性财政政策——基于偶然约束模型的分析

Economic Growth Lower Bound and Non-Linear Fiscal Policy ——Based on a DSGE Model with Occasional Binding Constraint

中国财政政策具有非线性特征,在常规时期采取温和的逆周期刺激政策,而在非常规时期采取保经济增长下限的强刺激政策。本文借助偶然约束模型对此进行了分析。强刺激财政政策能够实现保增长,但挤出了私人部门投资,并导致需求结构中消费的占比下降、产业结构中工业的占比上升。十年来,政府投资的边际正外部性不断下降,工业的边际负外部性不断上升,导致"四万亿"政策虽维持了经济稳定却大幅抑制了经济效率,恶化了社会总福利。

Fiscal policy is non-linear in China,normal in regular periods,but intensively stimulus in recession to keep economic growth rate above a lower bound.We build a DSGE model with occasional binding constraint to analyze the non-linear fiscal policies.The stimulus fiscal policies can keep economic growth,but crowd out the private sector investment,augment the proportion of investment in total demand and stimulate the proportion of manufacture in total supply."Four Trillion"stimulus fiscal policy in 2009 has worsen social welfare because of the decreasing marginal positive externality of government investment,and the increasing marginal negative externality of manufacture.