I don't know that either. I do know that I've made nothing less than ECONOMY PLUS on my trip to and from the Pacific region recently. I've had two first class legs only. From HNL-GUM and GUM-NRT. Got lucky on economy plus with me and wife, lady got upgraded to first so it freed up space for us on a NRT-SFO trip. That really helped alot. Any extra room adds up. The only advantage I see with Econo-plus seats is a bit more leg room, but not by a whole bunch. Nothing grows to your left and to your right. I would say its better than regular coach but nothing to get excited about if you weigh say more than 220 pounds and taller than 5'10. feet.. Best case scenario is an exit row seat which I got from GUM-MNL with an empty seat in the middle or better yet, you got the whole row to yourself. I got the exit row but it was all seats full, and me and a heavy set lady from RENO. Very cool lady on business there in Manila. I was filling her in so that she wouldn't freak upon landing in Manila.