We establish five facts about prices in the U.S. economy: (1) For consumer prices, the median frequency of nonsale price change is roughly half of what it is including sales (9-12% per month versus 19-20% per month for identical items; 11-13% per month versus 21-22% per month including product substitutions). The median frequency of price change for finished-goods producer prices is comparable to that of consumer prices excluding sales. (2) One-third of nonsale price changes are price decreases. (3) The frequency of price increases covaries strongly with inflation, whereas the frequency of price decreases and the size of price increases and price decreases do not. (4) The frequency of price change is highly seasonal: it is highest in the first quarter and then declines. (5) We find no evidence of upward-sloping hazard functions of price changes for individual products. We show that the first, second, and third facts are consistent with a benchmark menu-cost model, whereas the fourth and fifth facts are not. (c) 2008 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology..
Nakamura et al. (Wed,) studied this question.