Originally Posted by peasant

Simple answer - revenue management. CX are on a relatively sophisticated O&D PROS system that has the concept of ‘willingness to pay’. This translates into a floor price that you are happy to sell at, until you start running out of seats. Tends to produce stable prices that only rise close to departure once load factors go above 80% or peak seasons. The maths says that dropping below the floor price may sell more seats, but at less revenue. To fill the flight, use connecting traffic where willingness to pay is lower (as connecting vs non stop)

BA are on an old in house system (but have announced they are moving to Amadeus) that isn’t O&D, so tends to start with low prices, then increase the price with load factor.