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,...