We generalize the traditional, static Keynesian cross by deriving an intertemporal Keynesian cross for the dynamic output response to government spending and taxes in microfounded general equilibrium models. Intertemporal marginal propensities to consume (iMPCs) are sufficient statistics for this response, with fiscal multipliers depending only on the interaction between iMPCs and public deficits. We provide empirical estimates of iMPCs and argue that they are inconsistent with representative agent or two-agent models but can be matched by certain heterogeneous agent models. Models that match empirical iMPCs imply larger and more persistent output responses to deficit-financed fiscal policy, with cumulative spending multipliers above 1.

We show that in a broad class of menu cost models, the first-order dynamics of aggregate inflation in response to arbitrary shocks to aggregate costs are nearly the same as in Calvo models with suitably chosen Calvo adjustment frequencies. We first prove that the canonical menu cost model is first-order equivalent to a mixture of two time-dependent models, which reflect the extensive and intensive margins of price adjustment. We then show numerically that in any plausible parameterization, this mixture is well approximated by a single Calvo model. This close numerical fit carries over to other standard specifications of menu cost models. Thus, for shocks that are not too large, the Phillips curve for a menu cost model looks like the New Keynesian Phillips curve, but with a higher slope.