Standard consumption models assume a notional consumption flow that does not distinguish between nondurable and durable consumption. Such notional-consumption models generate notional marginal propensities to consume (MPC). By contrast, empirical work and policy discussions often highlight...

This lecture focuses on the costs of public debt when safe interest rates are low. I develop four arguments.First, I show that the current U.S. situation in which safe interest rates are expected to remain below growth rates for a long time, is more the historical norm than the exception. If the...

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...