Originally Posted by
MSPeconomist
The USA legacy carriers have always been nervous that adding premium economy would have the effect of cannibalizing business class ticket sales. One interpretation is that DL expects this, but has decided to add premium economy, either because they feel forced to by the competition or (and these reasons are somewhat related) because they believe that the increase in revenue they'll receive for premium economy will offset any losses from business class, given the different amounts of floor space taken by business versus premium economy seats.
Business class bookings fall into the following categories:
1) Paid business
2) Paid economy, upgrade to business
3) Award business
4) Non-rev
When airlines say they don't want to cannibalize business ticket sales they are referring to category 1. Delta has the breakdown of how many business tickets in each of the above categories. I think DL wants to keep the number of paid business tickets, category 1, the same, and expects reduction of J seats to impact categories 2, 3, and especially 4.