Originally Posted by fastair

Your assumptions are way off. Those are the number of IDBs, not DBs as a whole. And a very small % of oversales result in any type of DB due to no shows/misconnects. My guess is that the average sold out flight is oversold by at least a couple of %, not 0.012%, and the non-full flights benefit by an increase inventory to sale, allowing more seats to drop into the lower priced buckets. Constrain supply by 2-3% and in a market that is only partially elastic, where supply is matched to demand, and the cost to consumers, if passed on, goes up way more that 0.012%, likely at least a few %. On the plus side, labor costs might drop as this process is a labor sink to the airlines (soliciting, rebooking, processing are all labor intensive.)