MPCs, MPEs, and Multipliers: A Trilemma for New Keynesian Models

Abstract

We show that New Keynesian models with frictionless labor supply face a challenge: given standard parameters, they cannot simultaneously match plausible estimates of marginal propensities to consume (MPCs), marginal propensities to earn (MPEs), and fiscal multipliers. A HANK model with sticky wages provides a solution to this trilemma.