Using a VAR model that includes a survey measure of expected inflation, this article investigates the responses of expected inflation to temporary shocks to macroeconomic variables during three sample periods, 1953:1--1979:1, 1979:2--2001:1, and 1985:1--2007:1. Shocks to actual inflation, commodity prices, and expected inflation itself have been three major sources of movement in expected inflation, together explaining over 80 percent of the variability in expected inflation. Positive shocks to actual inflation, commodity prices, and expected inflation itself lead to increases in expected inflation that are large and long-lasting in the pre-1979 sample period, but muted and short-lived in post-1979 sample periods. Oil price shocks have only transitory effects on expected inflation. The positive response of expected inflation to higher oil prices found in the pre-1979 sample period is absent in post-1979 sample periods, suggesting that the Federal Reserve may have earned credibility.