First of all, Delta can't just order a bunch of A320's (well, they could, but that would be pretty stupid). It makes much better sense to use an aircraft you already have.Blue Dude said:I think the ultimate point was that if you're going to carry the same number of passengers, the airplane that does the job for the lowest trip cost wins even if the unit cost is higher. Which in this case, it isn't anyway. Only if given the same load factor (and revenue) does the lowest unit cost win. Song's extra 43 seats are nice if you can fill them, but since that's not usually the case, they're just a full-time expense with a very part-time benefit. If a typical load is 130 passengers, would you rather fly them on a plane with 156 seats, or one with 199 seats that costs 40% more for the trip?
Secondly, you are assuming quantity demanded is a constant, which is false.