Why do most prices rarely change?

Fuel prices are almost constantly changing, whilst prices paid for electrical appliances may remain stable for several months. For most products, prices tend to remain the same over weeks or even months. There is a simple explanation for this: it would be too expensive for companies to perpetually analyse market price changes. This is the conclusion reached by economists Mark N. Harris, Hervé Le Bihan and Patrick Sevestre after analysing the evolution of prices of several hundred industrial product pricess.