I didn't say I was rational about it. And if I was the company owner paying for it, it would bother me that something that I was paying for for my employee was being used by someone else for free. Push comes to shove, I would take the $1,500 and live with it.

I still wonder why the airlines don't offer something like this for a 50 percent upcharge. I think the demand is there.

This is exactly my point: there's no huge cost savings in it for any sizable company. Miles likely wouldn't enter the equation, it'd be $4-5k vs. $5-6k. Maybe when coach fares TATL/TPAC were $500-700 R/T on a more regular basis...but all of my business trips, usually bought 2-3 weeks in advance in a medium or high coach bucket are more like $1500-2000 R/T.

But you really aren't paying for 100% of the seat: you're paying for the armrest, some shoulder room, and the underseat storage area. And maybe part of the tray, a place to toss your magazine, etc. The presence of someone on the other side of the seat is moot. (I'd certainly claim that underseat storage though! )

Seat sold is occupied whether it has a body in it or not.. thus a fare is charged.

The $1500 is the tipping point for me.

I think Air New Zealand sort of does with its sky couches.

Depends, doesn't it? on a) where in Asia and b) how "far away" from $3k you consider the following - I've seen consolidator fares on AC from ORD to HKG recently for around $4,500 return in June, and if you're talking about the west-coast then OZ has LAX-HKG for under $4k and if you're prepared to slum it on MU then you can get it for $3.6.

Why would an airline sell a seat for 50% of the fare when they can also sell it to someone else for 100%?

The suggestion was made that when there was 3-across seating, that seats be offered on each side of an empty seat for a 50 percent premium. Thus the airline would not lose any money, and would actually gain revenue by not having to fool with the extra passenger. perhaps I should have been more plain; Obviously this would only apply in cases of 3-across seating.

That doesn't work.

Or more accurately, that only works in the case where both seats alongside such a seat were sold AND they both paid the premium for the empty seat.

But: why would I pay that premium if the other passenger already paid it, such that the seat will be left empty? You can't occupy half a seat. And if I were flying with a companion, I might pay the premium so we have three seats to ourselves. But then, again: there is no reason to pay the premium twice because I've already paid it once and a seat can't be 50% occupied. And in that case I can be sure of the seat being empty because I know the premium was paid.

The airline can't demand the premium be paid twice (apart form simply selling the seat at 100% of course) because they'd be offering the service to single seats but without the actual guarantee of the other neighbour paying the same premium, in which case the service would not be delivered.

The only thing they could do is block the middle seat and charge premium prices for window/aisle, adjusting the cabin as necessary to account for demand. In other words, a business/economy cabin that flexes based on demand.

Many airlines do this on short-haul: I've flown several different Airbuses (319's and 320's, I think) that did this. But I don't see it on long-haul - that tells me that airlines have indeed run plenty of simulations if not actual live tests and have instead focused on enhancing the real business class with better seats and amenities, not creating more finely differentiated options in coach. Your best bet in coach ends up being the premium economy offerings on a few carriers... The offer to formally pay 100% for the second seat is not always accepted - it's a popular topic on the boards here where the airline has a POS policy. (Specifically, the short skinny guy can't always just throw down cash for the 2nd seat.)

Obviously if the airline were to offer such a program, it would block off a few rows and they would only be bookable by those paying the 50 percent upcharge. So your traveling companion would have to sit on another row.

Of course, the problem with premium economy is that most generally offer only more legroom, and most planes have plenty of legroom for the average person. It's the width and having to touch and constantly jostle a stranger that makes coach seats so awful.

The only airline I can think of that has remotely close to enough legroom for the average person is United Economy Plus. (Among the U.S. majors and the European carriers I've flown...I realize there are probably others who have this kind of product.) Not really a premium economy product but the legroom itself is...passable. Usually 35" or so pitch.

The real problem is that most corporate travel policies don't account for premium economy. Most companies software requires you to buy cheapest economy, period. It's not a standardized enough product for companies to build into their international travel policies either. And you're definitely right on the width - especially on a Boeing, it's the shoulder room that is uncomfortable, even in exit row or UA E+.

Also on an Airbus widebody you don't have to share the spare seat with anyone since the seats are in 2's not 3's

That still leaves the airline with the potential for a whole bunch of unsold and unused seats.

who guarantees the empty seat, the employer or the airline? what happens when the airplane oversells, sees a seat for which no passenger checked in, and puts a standby or NRSA there? what if someone poaches the empty seat?