What accounts for the changes in US fiscal policy transmission?

Using vector autoregressions on U.S. time series for 1957-79 and 1983-2004, we find government spending shocks to have stronger effects on output, consumption, and wages in the earlier period. We try to account for this observation within a DSGE model featuring price rigidities and limited asset market participation. Specifically, we estimate the structural parameters of the model for both periods by matching impulse responses. Model-based counterfactual experiments suggest that most of the changes in fiscal policy transmission are accounted for by increased asset market participation and the more active monetary policy of the Volcker-Greenspan period.