We investigate the implications of changes in the structure of the U.S. economy for monetary policy effectiveness. Estimating a vector autoregression over the pre- and post-1980 periods, we provide evidence of a reduced effect of monetary policy shocks in the latter period. We estimate a structural model that replicates well the economy's response in both periods, and perform counterfactual experiments to determine the source of the change in the monetary transmission mechanism and in the economy's volatility. We find that by responding more strongly to inflation expectations, monetary policy has stabilized the economy more effectively in the post-1980 period.

This paper provides theory and evidence that distorted long-term interest rate expectations limit the effectiveness of monetary policy. Beliefs that depart from rational expectations break the tight link between policy rates and long-term interest rates, even when determined by the expectations hypothesis of the yield curve. Because long-term expectations are excessively sensitive to short-term interest rates, optimal policy is less aggressive relative to rational expectations. More aggressive policy leads to suboptimal volatility in long-term interest rates and aggregate demand through standard intertemporal substitution effects. These effects are quantitatively important in the United States over the postwar period.

This paper shows that the recent evidence that disaggregated prices are volatile does not necessarily challenge the hypothesis of price rigidity used in a large class of macroeconomic models. We document the effect of macroeconomic and sectoral disturbances by estimating a factor-augmented vector autoregression using a large set of macroeconomic indicators and disaggregated prices. Our main finding is that disaggregated prices appear sticky in response to macroeconomic and monetary disturbances, but flexible in response to sector-specific shocks. The observed flexibility of disaggregated prices reflects the fact that sector-specific shocks account on average for 85 percent of their monthly fluctuations.