Unconventional policies in state-dependent liquidity traps
研究在供给和需求驱动的流动性陷阱中，最优的非常规货币与财政金融政策，发现存款补贴和税收可有效应对通胀与产出权衡，且相机抉择与承诺政策福利效果几乎等同。
We characterize optimal unconventional monetary and fiscal-financial policies against supply- and demand-driven liquidity traps within a tractable New Keynesian model featuring a cash-in-advance constraint and a monetary policy cost channel. Deposit subsidies circumvent the inflation-output trade-off arising from stagflationary shocks and supply-driven liquidity traps by enabling negative nominal interest rates . Additionally, deposit taxes facilitate modest interest rate hikes to escape demand-driven deflationary traps. Notably, discretionary and commitment policies with deposit taxes / subsidies deliver virtually equivalent welfare gains, rendering time-inconsistent forward guidance schedules unnecessary. We also derive robust and implementable optimal policy rules when the sources of shocks are unknown.