An interesting point was raised in this thread: who pays for the service (and who pays for the employees.) I'm guessing the airports pay for the wheelchair attendants ...much like they pay for janitorial help out of airport funds. And am I correct in assuming the same is true for electric cart drivers ...even though they're driving CO-branded carts?

It appears the airlines themselves own the wheelchairs. Through my experience, the gate agents would say things like "ohh...this isn't one of our chairs" while the wheelchair attendants would say "we need to go find a Continental chair." So I'm also guessing that while the airports supply the attendants, its the actual airlines that provide the equipment...whether it be carts or chairs. (?)