Originally Posted by DCAstudent
OneWorld doesn't decide which inventories get which amount of miles. Blame Aer Lingus, not OW.
You get access to some of the best lounges in Europe thanks to OW, can buy tickets through other airlines to save money (see the thread on buying intra-European BA and IB tickets via AA.com to save), have easier connections, etc.
I think how many/whether AA miles you get for EI flights is decided by AAdv.