sticky prices https://scholar.google.com/scholar?hl=en&as_sdt=0%2C39&q=sticky+prices&btnG= https://scholar.google.com/scholar?hl=en&as_sdt=0%2C39&q=sti... roug

sticky prices https://scholar.google.com/scholar?hl=en&as_sdt=0%2C39&q=sticky+prices&btnG= https://scholar.google.com/scholar?hl=en&as_sdt=0%2C39&q=sti... roughly, changing prices has transactional and psychological effects, so suppliers hold out on price changes as long as possible, then do bigger changes (especially in non-liquid markets). So we see fewer big step changes in prices than smaller continuous changes (except for things that are traded frequently, like commodities). Also there is a herd effect with consumer pricing. Once a market leader raises a price, that makes it 'safe' for other firms to match the price change.