With　airlines　operating　in　an　imperfectly　competitive　market　environment,　this　study　focuses　on　the　important　role　of　price　variables.　A　network　data　envelopment　analysis　(NDEA)-based　Nerlovian　profit　inefficiency　model　for　a　group　of　international　airlines　was　proposed,　in　which　the　property　of　unstorable　intermediate　outputs　in　the　air　transport　industry　is　considered.　The　profit　inefficiency　of　airlines　is　then　decomposed　into　two　stages:　cost　inefficiency　in　the　production　stage　and　revenue　inefficiency　in　the　consumption　stage.　Both　cost　inefficiency　and　revenue　inefficiency　are　further　decomposed　into　three　sub-inefficiencies:　technical　inefficiency,　price　inefficiency,　and　allocation　inefficiency.　The　empirical　results　show　that　all　airlines　are　profit　inefficient　and　their　profit　inefficiency　is　due　to　different　sub-inefficiency　components.　In　terms　of　overall　profit　inefficiency,　the　revenue　inefficiency　at　the　consumption　stage　is　the　main　cause,　and　price　inefficiency　is　a　major　component　of　revenue　inefficiency　on　average.　©　2022　Elsevier　Ltd