Originally Posted by atcanobbio

Airbus already does this. They base their interior cabin width on 18-inch wide seats. Pretty much forcing airlines to go with that seat width since Adding another seat would make it very unattractive (ie 9-across A330, 10-across A350). Don't get me wrong, some airlines just think $$$ and go the unattractive route but those few and far in between.

I think Boeing should adopt the same philosophy just for the sake of passenger comfort. Flight these days can easily be 12-hrs long. Add to that a 17-inch seat with 31-inch pitch...it's a nightmare!!!! (IMO)