I am sitting in the airport now about to fly back to Phoenix. I generally fly America West / US Airways, because they have a hub in Phoenix and doing so maximizes my chance both of getting non-stop flights as well as accumulating a meaningful frequent flier balance with a singe airline.
After way too many round trips, I have the following observation: I am much more likely to get an elite upgrade returning home than on the outbound leg. I have seen this effect both flying the hub airline out of Phoenix and previously flying United out of Denver. Now, as a hub city, Phoenix has a disproportionate number of US Airways elite members, just as Denver has a disproportionate number of United elite members. So competing with a lot of other elite members for limited upgrade seats is understandable out of Phoenix, but shouldn't it be symmetric coming back? I have three theories:
- Observer error, though I will say I have a fairly large number of observation points to many different cities from two different hub cities
- I am flying when the Elite's like to fly outbound, but I tend to take unpopular flights back. Possible. Most business travelers tend to fly outbound in the morning on the first flight, but they may all come back different times of day depending on their business. This is one potential asymmetry.
- The airlines give preference on upgrades to through passengers. I have never heard this, but it might explain it. Outbound from a hub, many of the people on my flight are on the second flight, having just changed planes. Going home, towards a hub, everyone is in the same boat as me, on their first leg. I don't think the airlines differentiate, but this is the only other asymmetry I can come up with.