This paper studies price stability and debt sustainability when the real rate exceeds trend growth (r g) in a New Keynesian model with endogenous technology growth through R&D. Under debt-stabilizing ("passive") fiscal policy the Taylor principle is not sufficient for determinacy. Instead,...

We examine global economic dynamics under learning in a New Keynesian model in which the interest-rate rule is subject to the zero lower bound. Under normal monetary and fiscal policy, the intended steady state is locally but not globally stable. Large pessimistic shocks to expectations can lead...