Nonsense! Under the pre-choice, assume the same distribution of meal loads, the probability of not getting your first choice are still the same but the key difference is the amount of uncertain people is reduced hence there is overall reduction of the number of people who won't get their first choice.

There is a good reason why AA implemented the pre-choice on their flights.

I always pre-order on AA. For last week flight I did as usual and got my choice (breakfast omelette). The guy seated beside me, in 3C, that did not pre-order, could only have the oatmeal as it was the only thing left. He was less than pleased...

Ok, but giving people the choice to preorder will help things. I would look at the menu and be happy to preorder, I am quite stable with food if i am given a choice of options! It will make things overall better.

Yes absolutely.

Absolutely!


Yes, if he did not preorder that is his problem and he can't blame the airline for it or for being stingy. In this case, AA saying we don't like wasting food so won't have many choices is fully justified! They did 'offer the option to preselect anyway!'

So what do you propose then? It is clear BA are trying to cut waste so if they do not have pre order and a limited choice on board, that will just make passengers more and more unhappy!

Apologies. We actually agree. I made the mistake of making a cup of tea in the middle of typing that!

Edited my post now.

I think pre-ordering is fine (although I agree with others that I won't always want to as I don't always know in advance what I fancy). However, what I'd propose is to make pre-ordering better by using the reduced waste that ensues and saved costs for airlines by expanding the pre-ordered options as opposed to limiting pre-ordering to the 'normal' menu (ie make it 'book the cook' instead of 'AA style'). By expanding options if pre-ordered, you'd then encourage more people to pre-order as they'd know they will only have - say - 4 options to choose from onboard as opposed to 10 if pre-ordered.

^ (actually I did wonder as I agreed with your explanation, just not with your mistyped conclusion! ) Hope you enjoyed the tea though!!

No actually, that probability of someone not getting their first choice will increase. The key is that not getting your first choice is not random error but sampling error, ie BA actually know what proportion of people tend to choose the beef, chicken, etc dishes and organise loads accordingly (they don't just take, say, 5 of each, but maybe 7 beef, 4 chicken, 2 salads, etc).

If all BA F customers were flying on one gigantic first class flight at the same time, BA's prediction would thus be extremely accurate and the proportion not getting their choice would be extremely low. However, as you reduce the sample size (which is what you do when most people have chosen their main through pre-order and you only cater for the rest), sampling error increases and so does the 'risk' that the sample will not be representative of the whole will increase accordingly.

Often wondered why they dont do big bowls of stuff and offer you a portion and communal cheese boards etc
Bring back the display trolley!
Do any airlines do this? I know cathay partially does

In long haul premium classes, many! For instance, TK, OS, and RJ do it for their starters, CX does it for cheese and fruit, AZ does it for all dishes. Many airlines do it for cheese boards and/or side vegetables.

I agree it is usually nice, and many airlines train their staff to plate food nicely anyway so why not use that skill. It also typically allows people to sample more dishes rather than choose a full portion of one thing.

Good point orbitmic. I admit I used an oversimplified assumption to make my argument short. But my original point still holds. The sampling error difference between 20 and 40 people (assume 20 out of 40 people in CW pre-order) is negligible. In fact sampling error is precisely an argument why airline should make people pre-order because that is only way for them to accurately making predictions for a small sample size (a CW cabin of 40 for example). As you said, if it's just one large premium cabin per year, then all the airline analytics would be right on the mark.

By the same token, you can see what you don't like or cannot eat and ensure that you do not get stuck with that.

Knowing BA, they will 'charge' you a fee to preselect your food. 20 GBP please.
If you don't want to pay, be at the mercy of not having your first choice available on CW = )

I hope i didn't give them any ideas with this 'innovative enhancement'.

Actually sampling error increases disproportionally when moving to smaller n and larger number of values, so there is a much bigger impact between 20 and 40 (definitely not negligible) than between 2000 and 4000 (especially if we add that randomness of the sampling is actually an untenable assumption here), and even bigger 10 and 20 and massive between 2 and 4.

For instance a full F cabin is 14 people and offers a choice of 5 mains. It is aa very small n already for 5 categorical values, so on 100%, there would almost certainly be some error, but airlines hedge against it by over-catering, I think at 130% in F. Now imagine 9 people pre-order so BA need to apply their estimate for 5 people. They will load 6 (120%) or 7 (140%) dishes so either 3 or 4 of the five options will be in a load of 1. Chances that things will go wrong will be high, in fact at that level, there is more than 50% chance at least one person will not get their first choice if we assume BA's model was absolutely right!!

In CW, there are more people and only 4 options but I think overcatering is at 110% for mains if I remember, probably less on night flights. Now again, on a 60+ cabin you'll be fine but when 40 or 50 of them pre-order the rest may well experience problems.

In fact, most FTers already know this (if not necessarily the mechanism that leads to it) because the vast majority of reported choice problems we get are on relatively empty cabins.

The sampling error (assume no biases) is a function of the sqrt of the sample size. From 2 to 4 or 20 to 40, the difference in both cases is a multiple of sqrt(2). I think we only disagree on the qualitative meaning of negligible here. For 20 people, the error is about 20% and for 40 it is about 15%. For me that is a small difference.

For your F cabin example, other errors such as rounding becomes dominant since you can't have 1.75 chicken, 3.5 pork and 0.75 fish..


For the CW cabin, if 35/40 pre-orders, then you can overload the remaining meals by 200% and still come out ahead of the expected 115% error mark for the entire cabin.

On the last point: but that's the whole point: they won't overcater more, their whole idea is to reduce costs as much as possible, and certainly not to use the exact prediction of part of the group to become more generous on the way to treat those who do not pre-assign. Moreover, it would create exactly the wrong incentive structure as BA's goal is to push as near 100% of pax as possible to pre-order, so if anything, overcatering rates will go down, not up. And yes, rounding error and more will add to sampling error.

On your first point, I certainly don't want to start what wounds like a professional argument or we'll bore everyone, but there are many different ways to measure sampling error. Most will (rightly) take into account the characteristics of the variable you are trying to estimate and not only the population and sample sizes which of course matter a lot. Again, for the benefit of our Ft crowd, it makes a lot of intuitive sense to do that: let's say that you have a population of 1000 and a sample of 31. If you are using that sample to estimate gender (two values with uniform distribution), chances are that your estimation will be pretty good. However, if you use that very same sample to estimate the day of the month people are born (31 values with uniform distribution) chances are that your estimates will be pretty poor.

As you say, we can disagree on what constitutes marginal or sizeable in theory, but I'm not making an abstract theoretical argument but rather a practical one: in the case we are talking about, we may well end up with 5 people and 5 options with skewed distribution: there will be error and some people simply won't get their first choice, and it will happen more often than before even though an increasing number of people will have been secured into a 'true' choice.

Now again, concretely and commercially, my suggestion is that the best answer, the 'win win scenario', is for BA to create a genuine incentive for pre-order by using pre-order to give people significant extra choice. You will never reach 100% of pre-orders but commercially, it makes it much easier to claim that whilst the 1 or 2 people left in the cabin will almost certainly not get their first choice, they will get what they deserve for not using that sublime book the cook facility with its 10 or 20 options!

So, in summary, not Nonsense! then.

Glad we've cleared that up.