Optimal fiscal and monetary policy with occasionally binding zero bound constraints

This paper studies optimal government spending and monetary policy when the nominal interest rate is subject to the zero lower bound constraint in a stochastic New Keynesian economy. I find that the government chooses to increase its spending when at the zero lower bound by a substantially larger amount in the stochastic environment than it would in the deterministic environment. The presence of uncertainty creates a unique time-consistency problem if the steady-state is inefficient. Although access to government spending policy increases welfare in the face of a large deflationary shock, it decreases welfare during normal times as the government reduces the nominal interest rate less aggressively before reaching the zero lower bound