Originally Posted by
prestonh
RPM's are a very general measure of topline performance among airlines. But it really means very little with regard to the question you ask on different fares/classes. To get to that information, you should look at PRASM (also known as yield), passenger revenue per available seat mile. The disclosures in the 10-K's look at this in some depth. Redeemed Award seats are technically revenue but only because the liability was booked as a CGS offset when the miles were earned or awarded (i.e. as a sale to CC vendor or promo).
Close but not correct. PRASM (or often RASM, which includes all revenue on the flight including cargo/freight/mail) is NOT the same as yield. Yield refers to an individual passenger's revenue on that flight divided by the miles. It cannot be calculated on a flight level or rolled up across the system. RASM includes free tickets, empty seats...yadda yadda...it is revenue per AVAILABLE seat miles. Yield is simply one sold seat/miles.
A low load flight with a high yield can net far less (or more depending) than a full flight filled with low yield passengers. The overall factor when judging profitability (and when compared to costs) is RASM, not yield, or even PRASM.
Edit: Yield CAN be rolled up, but one must (if on a flight level) adjust for load factor (hence the RASM is more useful.)