This is but one example of the way costs are moved from JQ to mainline:
A couple of years ago Qantas was training quite a few guys on the 330. There was limited sim availability in Qantas.
In order to facilitate Jetstars requirements of the sims, Qantas sent its crews overseas to train in other organizations sims. This meant that the QF crews needed to be transported, accomodated, paid allowances, not to mention the cost of the actual training.
This applied to maybe 50 guys..an enormous cost, borne by mainline. It would have been hidden in the bottom line as a training cost, but with no explanation required.
As I said, just one example.