Optimal Fiscal Policy in a Monetary Union with Zero Interest Rate Constraint
- 经济学院－已发表论文 
文章将零利率约束引入两国新凯恩斯模型来研究货币联盟的最优财政政策。财政政策分承诺规则和相机抉择两种情况,当本国遭受技术冲击时,无论政策是承诺规则还是相机抉择,本国都将增加政府支出和政府债务,外国则是减少政府支出和债务,且零利率约束时的两国财政支出和政府债务均大于无零利率约束时。福利分析表明,承诺规则下的零利率约束恶化了本国福利,但会改善外国福利,整体上恶化货币联盟福利;相机抉择下的零利率约束恶化了本国、外国及货币联盟福利;无论有无零利率约束,承诺规则的货币联盟福利损失均大于相机抉择。This paper introduces the zero interest rate constraints into a two-country New Keynesian model to study the optimal fiscal policy in a monetary union. Fiscal policy can be devided into two circumstances,commitment and discretion. This paper shows that when there is a technology shock in home country,no matter the policy is under commitment or discretion,home country will increase government spending and debt,and foreign country will decrease them. Both governments' spendings and debts under zero interest rate constraints exceed that without zero bound. Welfare analysis shows that,zero bond decreases the welfare of home country,improves that of foreign country,and decreases that of the whole monetary union under commitment policy; while zero bond decreases the welfares of home country,foreign country,and the monetary union under discretion policy; the welfare loss of the monetory union under commitment policy is larger than that under discretion policy.