Why Do Airlines Oversell (& Overbook) Flights? Here Are The Main Causes...

You overlook one important thing. There are an uncountable number of passengers who are able to book and fly when and where they wish to travel even though, unknown to them, their flight is actually full. Otherwise they would have made less satisfactory choices to to a similar journey.

And it isn’t actually the case that an airline always has been paid twice for the same seat. Misconnections need to be accommodated on other flights and for inter-line bookings, the airline doesn’t get their money until the passenger actually travels.

The causes are greed and flim-flam .

You're overlooking a very big reason why these oversales happen at peak periods when airlines often tend not to overbook their flights as no-shows tend to be much lower when families are traveling. That reason is INAD/DEPU passengers. If you land somewhere where 10 passengers are denied entry and ordered returned, that is 10 passengers on your return flight that you need to bump to accomodate those. This can create a snowball effect over the course of multiple days and really mess up revenue management.

Sean -
Interesting comment - can you elaborate on who is "responsible" when pass are denied entry into a country and what is the responsibility of the Airline to accommodate passengers. I can assume a role if they allowed pass to board/travel if they didn't confirm valid passports/visa/etc?

Because we, especially in the US, allow lobbyists who legally bribe our elected representatives to vote against the peoples’ best interests, and the result is often that workers and consumers get screwed, while the wealthy and influential get rewarded. That’s why airlines get away with this.

You joke, but you’re not wrong.

The ‘missed connections’ and re-accommodating passengers is a different category all-together, more of a ‘stand-by’ situation; whereas, what this post was focused on is people who do actually pay for that specific flight, schedule, etc. So, let’s not conflate the two and give the airlines unlimited passes to screw over anyone and everyone on a whim. Ultimately, these airlines are businesses, and in many cases they make a ‘business’ decision on who to serve and when. Where that is the case and a passenger is denied based on overbooking, they should be compensated extra. Many countries legislate such rules; the US should do so as well.

Well said, Sean. You’ve had operational experience running airlines, so you would know. It’s generally bad practice to overbook. The issue is that in the US, corporations, including airlines, think they are unstoppable. That they can upset consumers, because their real customers are majority shareholders. As others have said before, these are becoming ‘credit cards with wings’ mere loss-leaders for the big banks and their points/miles programs.

Airlines have invested considerably in algos that enable them to overbook flights without in the end needing to have volunteers or involuntary denied boardings. Anyone over the past few years that has volunteered thinking they'd end up with a voucher/credit or free flight has in the end told to board-and finding no space around their seat for their carryon. Typically overselling is seen on popular flights at popular times-like Hawaii during the holidays.

The username with 1990, gets it! Plain old capitalist greed.

Oh, and we, the people, can still demand better, peacefully and effectively, but we’re often distracted by corporate-backed propaganda, which deflates our motivation to seek better outcomes and guardrails to protect us against such bad practices. So, ignore the naysayers, demand better. We deserve actual air passenger rights legislation in the US, akin to EU/UK261, Canada’s APPR.

Algorithms are fancy ways to describe ‘policies’… it’s all a business decision, and these for-profit companies are gaming their own passengers. Perhaps, we shouldn’t allow such predatory practices anymore… Congress, DOT, etc. can stop this any time they want. Oh, wait, A4A just delivered a million dollars to the committee members who decide this. Huh.

But if a passenger flies FRA-JFK-BNA and misses the connection in JFK, accommodating them on the next JFK-BNA flight if it is already full will involve someone being denied boarding.
And it does seem that connecting passengers are given priority, so it is someone who booked just JFK-BNA who will be denied; due to accommodating the connecting passenger.

@George Romey
Thank you for that advice.
So if offering, one should do so on a fill-or-kill basis, rather than giving the airline an option to execute.

@michael
https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/frequently-asked-questions/about-basics.html has:
"After I have my visa, I will be able to enter the U.S., correct?
A visa does not guarantee entry into the United States. A visa allows a foreign citizen to travel to the U.S. port-of-entry, and the Department of Homeland Security U.S. Customs and Border Protection (CBP) immigration inspector authorizes or denies admission to the United States. See Admissions on the CBP website."

@Sean M.
I can see the implications of passengers being denied entry.
But I can't get the first sentence to make sense - should I swap "oversale" and "overbook"?

It might help the airlines if they published some high level figures.
E.g. "On *average* we oversell flights by 2%, but we deny boarding on less than 0.05% of flights."

So long as compensation for denied boarding is generous, and a voluntary mechanism assures this, I don't see why there is any cause for complaint - it achieves a more efficient use of resources.

BA once shared the fascinating number that a seat on one of their intercontinental flights out of Heathrow is confirmed between 8-10 times before departure.

Of course, not all of that is due to overselling, there are a myriad of factors at play. But (in contrast to what Lucky is telling you), passenger aviation is mostly a logistics business.

Ah, so, ignore reality; humans are just cargo; no rights, responsibilities, obligations, differences in class of service, schedule, routing, or whatever. Just a Point A to Point B. That’s all… /s

Lucky,
The reason is simple.
For the same reasons why bloggers exaggerate (or shill credit cards) when they write.
To maximize profits / readership / ad revenues etc.
“SQ Hidden lounge in CGK”!
WOW!

While change fees are gone, they remain in ticket pricing of changed booking. If I bought a ticket weeks ago, my ticket may have the lowest fare but my changed date may I longer have the lowest fare in that category.On arecent flight I
wanted to come home three days early but UA wanted about -$3,000 extra even though the original ticket cost $5,600 and there were numerous seats availabe

‘It’s a widely accepted practice in the airline industry that airlines will sell more tickets for a given flight than there are seats.’

Nope.
It’s a widely ACKNOWLEDGED practice in the airline industry that airlines selL…..

Nobody accepts it. It’s just a fact.

After seeing the inside from a pilots perspective i think flights are MUCH more often overbooked than oversold. It’s not that they purposely sell too many seats, it’s that things change. Maybe they have to deadhead crews unexpectedly, maybe there were flight cancellations and Elite members have been put on full flights, maybe there are equipment issues with the airplane that required the flight to depart with empty seats. That’s frequently the reason

People take lower fares for granted and curse overbooking.

It's those oversold that subsidize your lower fares.

The greed here are the passengers who wants it both ways.

While it would never be perfect, airlines are getting much better.
I feel in the last 10 years, airlines have asked for a much fewer volunteers.

In Asian countries, overlooking flights is illegal due to the very strong customer respect laws. Hence Dr Chong's confusion.

Jess, it was Dr. Dao, and he’s a Vietnamese American (hero). We’ve gone over this before…

Corporate shill, says what?

Exactly. And we should push back more effectively by demanding our government better regulate these bad practices.

My aunt used to work for AA (retired around 1990), but one of her jobs there was to review flight lists and see if Bob Smith booked a seat on four flights from Boston to NYC for his Monday meeting, and then determine that they could sell an extra ticket for each of those flights knowing that Bob was only going to be on one of them. For business travelers this was common practice to book a number of flights and then cancel whatever they didn't use, but the airlines needed to make revenue for those flights that the business person cancelled their ticket.