If they say it on Twitter, it must be true
Do the French really want to stop air travel?
You might remember having heard of a French poll about air travel during the last days of September or the first days of October. The results of that poll seemed to imply that 41% of the French population is in favor of limiting everyone to having four air flights in their entire life.
That seems like a considerable amount of support for a very restricting measure in the name of fighting climate change, a level of support that might make it possible to enact this restriction in the medium term.
The French company that made the poll, Consumer science & analytics or CSA, clearly states that the motivation for the poll was to assess the support among the French public for a proposal made last May by French activist Jean-Marc Jancovici.
This last May 30, the engineer Jean-Marc Jancovici, an expert in the subject of climate change, has proposed again to drastically limit airplane flights, and has declared it essential to put in place a quota of 4 flights per person in their entire life. This proposal has elicited many reactions, for and against it.
CSA calls itself a Marketing mix modeling company, which I interpret as saying: we are a marketing company but we actually know a thing or two about statistics, and it did the poll at the request of HERE, a subsidiary of Vivendi the French media holding company. Apparently HERE is just too cool to give a precise definition of who they are on their website.
We are HERE to help you navigate through the uncertainty of these changing times,
Bringing out your destinations’ and business’ most hidden assets,
Creating a one of a kind coalition of experts to imagine, create, and set up innovative solutions to engage with international tourists.We are HERE to build tomorrow’s tourism, meeting both business and wanderlust imperatives.
We are HERE to inspire each and every traveler,
We are HERE to have them book their next trip.We are HERE because we believe tourism is entering an exciting new era,
We are HERE because we care,
We are here so you get there.We are HERE
Powering meaningful travel.
But from Vivendi’s 2021 Annual Report it seems that HERE is a project started in 2021 by three Vivendi subsidiaries - Havas (advertising and public relations company), Editis (publishing) and Prisma Media (magazine publishing) - to offer support to the Covid-19 beleaguered world tourism industry on its way to recovery.
So let’s assume the motivation for HERE was to assess how much support there is among the general public for what they call responsible tourism. Nothing unusual.
What seems unusual to me is that this was an online poll. Online polls seem like the cheapest but also less reliable polls there are. What about the sample?
The sample was 1,010 French adults apparently (the press release is not clear about this) divided into age strata. There’s no more information about the methodology of the poll in HERE’s press release.
So far not great, but not terrible either.
Also, according to HERE’s website: flows of tourists are increasing globally, travelers are more demanding and complex while the planet cannot afford our current tourism habits anymore. Cannot afford. Not the kind of neutral statement that would reassure any critic suspecting of a predisposition for a certain poll result on HERE’s part.
But then CSA should have a motivation to conduct the poll in the most equanimous and neutral way possible, considering their reputation is on the line. Well, not really, since CSA is also a subsidiary of Havas.
While researching HERE and CSA I also came across this recent (five months ago) job posting by Philippine van Tichelen, general director of HERE:
The HERE team is looking for a new 🚀 rock star 🚀 to take over ... from July.
We are looking for a talent :
- Fond of travel and concerned about sustainable travel
Fond of travel? Can the planet afford that much traveling?
Looking at the results
Regrettably I can’t check the raw data for the poll, or even the exact questions asked as part of the poll, but we do have some disaggregated data from the results.
When asked where would they go if they were restricted to just four flights in their whole life, the four most common responses were: the US (31%), Canada (14%), Japan (13%) and Australia (11%). This is good, as it hints at respondents actually understanding the question and understanding the consequences of the drastic measure they are being asked to evaluate. They mostly chose destinations far away from France because that is the reasonable answer to that question.
But looking at the aggregated figures for each continent (actually six world regions because the Middle East was considered as its own region) it becomes immediately clear that the total adds up to more than 100%. This is because each respondent could answer with four destinations making it possible to reach a total of 400% by adding up the four possible answers of each respondent. So that 31% of respondents who apparently answered they would like one of those flights to be to the US could actually be a 7% of respondents who chose to have all four flights to the US and another 3% of respondents who chose one flight to the US, or another similar combination of answers.
That means those four countries far from France I just mentioned, the US, Canada, Japan and Australia, don’t make up 69% out of a 100%, but only 69% out of a 400% total. Did most respondents really choose countries far away from France?
The answer is still yes, but a qualified yes.
The sum of all destinations outside of Europe gives a total of 167% out of 400%. That is less than half of all possible destinations, but is much more than half of all destinations chosen by the respondents which is 216% out of 400%.
Still, that makes me question whether people who chose destinations in Europe (49% out of the possible 400%) actually understood what they were being asked. You can reach most destinations in Europe by train departing from France, while for destinations outside of Europe this is simply impossible or not feasible1. In fact 9% chose as destination France, which confirms that at least some respondents did not understand the poll.
And the next four more common chosen destinations in Europe were: Italy, Greece, Iceland, Spain. Which again corroborates that some of those who chose destinations in Europe did understand the poll (Iceland, maybe Greece), but some selected countries neighboring France in all likelihood because they did not understand what was being asked.
The common good
Why is there such a big difference between the share of all possible destinations, the ones that could make up to a 400%, and the share of all chosen destinations? Because 39% of all respondents did not choose any destination. That 39% is the sum of 36% who said they would not go anywhere and 3% who didn’t know where to go, and it’s very similar to the 41% who said they support the lifetime restriction of four flights.
This could be interpreted in the following way: respondents who supported the restriction of four flights were then not given the option of selecting the four destinations for their four flights. But this interpretation does not make any sense. You are not being inconsistent by supporting the restriction and having strong preferences for the four flights you want to take and, in the event of the restriction being enacted, taking those four flights. If the restriction is implemented, you could still take those flights without contradiction.
The interpretation that makes sense is that out of the 41% who supported the restriction 39%, or at least 36%, do not have any intention of taking any flights in the future regardless of the restriction being enacted or not.
In fact, 29% of French people had never flown on an airplane as of 2013.2
We can’t know, because the poll apparently didn’t ask, if all respondents who have never flown are also supporters of the restriction. Assuming that is the case, three quarters of supporters of the restriction would be people who have never flown. I don’t have any use for it, so you should not have any access to it.
Younger but not…
Another result that caught my attention was that 48% of respondents between the ages of 18 and 35 said they supported the restriction, and 59% of those between 18 and 24. For the 18 to 35 y.o. range that is seven percentage points more than the general population, and even though the press release of the poll doesn’t imply this, it could be construed if we take the common perception that younger people are more concerned about the environment as an indication that support for the restriction is increasing or will necessarily increase in the future.
Let’s do a quick check. Assume the chance of flying for a French person in any one year of her life is 5%. To simplify the calculation I’ll assume there are no French people under the age of 18, and everybody lives until 80, a total of 63 years. I’ll also assume the chance of flying is the same for any one year (it probably goes down after 70 or 75), because it simplifies the calculations and doesn’t affect the results. Given these assumptions you can see in the next graph the cumulative chance of having already flown at least once in their life in any one year of somebody’s life, starting with a 5% cumulative chance for 18 year olds (5% chance per year, just having lived one year) and reaching a 96% chance of having flown at least once in their life for an 80 year old.
The purpose of this graph is to point out as clearly as possible that younger people, say 18 to 35 years old, have flown less than older people, and this is to be expected. In fact for the previously stated assumptions only 36.37% of people in the range of 18 to 35 y.o. would have flown at least once in their lives. That is compared to 71% of all people having flown at least once in their life, which is equivalent to 29% of people not having ever flown (I chose the 5% chance not because it is a nice round number, but because it gives the exact 71% chance that I was looking for).
You could criticize the previous graph based on the fact that people flew much less in the 70’s and 80’s and so current 75 year olds probably had a lower chance of flying when they were 18 or 28 compared to current 18 year olds or 28 year olds. That might transform the previous curve into an inverted U curve but still wouldn’t change the result that French 18 to 35 year olds almost certainly have a higher than 29% chance of never having flown in their lives. In fact for the previous assumptions the chance of them never having flown is 63%, and for 18 to 24 y.o. it’s 82%.
So no, there is no trend towards younger people being more in favor of restricting flight when you take out the confounding factor of I have not flown so I don’t care if no one else can. You just need for the percentage of people not having flown to increase from 29% to 36%, a seven percent increase, for young people compared to all people to explain the increase in support for the restriction among young people. And as I showed in the previous graph it’s probably much more than a 7% increase in young people not having flown compared to all people.
And this is confirmed by the 59% support that the poll reports for 18 to 24 year olds, which is an 18 percentage point increase over the 41% support of the general population, but much lower than the 53 percentage point increase in never having flown for that age range.
To sum up:
The methodology of this poll is suspect. The fact that the pollster (CSA) is a subsidiary of the same holding company who owns the company who requested the poll (HERE) makes it hard to trust the neutrality of the poll.
Many respondents seem not to have understood what they were being asked. Doing a back of the envelope calculation, limited by not having all the results of the poll, I came up with 5% to 39% of respondents.
Respondents should have been asked if they had ever flown before in their life. If they were asked and the results of that question were simply not published by HERE and CSA that would be even worse for the credibility of this poll. Maybe as much as three quarters of respondents who supported the restriction might be people who have never flown in their life.
The implied (possibly, I have to acknowledge they don’t emphasize this result) trend of younger people supporting the restriction more than older people, and likely increased support in the future, is probably bogus. Again, this could be evaluated with more certainty if they had published all the data for the poll, including age for every respondent.
You could take this poll at face value while remembering that many people will be in favor of restrictions that don’t affect them personally. But I would advise against taking this poll as implying that there is widespread support for restricting air travel or that such support is increasing.
I understand that if flying was banned you could make an argument for traveling between continents by ship. But that would defeat the purpose of the flying ban being justified on environmental grounds as ships have to burn fuel to navigate. I’m assuming respondents took this into consideration when answering.
The percentage for the US appears to be something in the range of 13% to 18%.