True That Every Premium Economy Row Really Costs An Airline Rows Of Economy Seats?

A question circulating among travelers is whether every premium economy row really forces airlines to give up rows of standard economy. An analysis focused on United Airlines’ Boeing 777-300ERs when they arrived in 2016 explains how that “simple trade” doesn’t always hold. Initially, the aircraft carried 60 Polaris, 102 Economy Plus, and 204 economy seats (366 total). After United rolled out Premium Plus, it removed the first four rows of Economy Plus and added three rows of Premium Plus, bringing capacity to 350 seats (60 Polaris, 24 Premium Plus, 62 Economy Plus, 204 economy). Pitch differences exist—30–32 inches in economy versus about 38–42 in premium economy—but seat width can reduce capacity more than row swaps. The report notes United installed 24 Premium Plus seats in space previously used by 40 Economy Plus.