How does the need to preserve government debt sustainability affect the optimal monetary and fiscal policy response to a liquidity trap? To provide an answer, we employ a small stochastic New Keynesian model with a zero bound on nominal interest rates and characterize optimal time-consistent...

I characterize optimal monetary and fiscal policy in a stochastic New Keynesian model when nominal interest rates may occasionally hit the zero lower bound. The benevolent policymaker controls the short-term nominal interest rate and the level of government spending. Under discretionary policy,...

Even when the policy rate is currently not constrained by its effective lower bound (ELB), the possibility that the policy rate will become constrained in the future lowers today's inflation by creating tail risk in future inflation and thus reducing expected inflation. In an empirically rich...