We present an incomplete markets model to understand the costs and benefits of increasing government debt in a low interest rate environment. Higher risk increases the demand for safe assets, lowering the natural rate of interest below zero, constraining monetary policy at the zero lower bound,...

We show analytically that whether incomplete markets resolve New Keynesian “paradoxes” depends primarily on the cyclicality of income risk, rather than marginal propensity to consume (MPC) heterogeneity. Incomplete markets reduce the effectiveness of forward guidance and multipliers in a...