Quantifying the Uncertainty about the Fit of a New Keynesian Pricing Model: Extended Version

Recent studies by Gali and Gertler (1999) and Sbordone (2002) conclude that a theoretical inflation series implied by the forward-looking New Keynesian pricing model of Calvo (1983) fits post-1960 U.S. inflation closely. Their theoretical inflation series is conditional on (i) a reduced-form forecasting process for real marginal cost; and (ii) the calibration of the structural pricing equation implied by the Calvo model. The present paper shows that both of these determinants are surrounded by considerable uncertainty. When quantifying the impact of this uncertainty on theoretical inflation, I find that we can no longer say whether the Calvo model explains observed inflation dynamics very well or very poorly.