five facts about prices a reevaluation of menu cost models emi nakamura and j on steinsson harvard university january 3 2007 abstract we establish in the us economy 1 median implied duration consumer when sales are excluded at product level is between 8 11 months finished goods producer 7 2 one third regular price changes decreases frequency increases responds strongly to inflation while size do not 4 change highly seasonal it highest 1st quarter lowest 4th 5 hazard function for individual downward sloping first few then flat except large spike 12 services all these based cpi microdata new comprehensive data set that construct from raw production files underlying ppi show 2nd 3rd