More Lessons from Taking an AK Model to the Data.

We take an AK model to the PWT data. In the model both technology (intratemporal) and investment (intertemporal) shocks determine the variation of the growth rate. In earlier work we looked at singular models where we extracted only the technology shock using the policy functions from dynamic optimality. Here we recover time series for both shocks for a panel of countries and we isolate what we believe are pervasive patterns in macroeconomic models and postwar data: a negative correlation between intra and intertemporal shocks, and a somewhat lesser role for the intertemporal shock.