Why Fly? Prudential Value, Climate Change, and the Ethics of Long-distance Leisure Travel

We argue that the prudential benefits of long-distance leisure travel can justify such trips even though there are strong and important reasons against long-distance flying. This is because prudential benefits can render otherwise impermissible actions permissible, and because, according to dominant theories about wellbeing, long-distance leisure travel provides significant prudential benefits. However, this ‘wellbeing argument’ for long-distance leisure travel must be qualified in two ways. First, because travellers are epistemically privileged with respect to knowledge about what is good for them, they must look critically at their own assessment of the prudential benefits of a trip. Second, the wellbeing argument is unlikely to support prudential arguments for long-distance leisure trips made by frequent flyers.


Introduction
Should we refrain from taking long-distance flights?The answer to this question may seem straightforward.One long-distance aeroplane trip from Paris to New York amounts to 1.9 tons of CO 2 emissions.1But keeping within the limits of the Paris Agreement requires reducing CO 2 emissions to an average of 2-2.5 tons of CO 2 emissions per capita per year.Long-distance travel currently produces roughly 5% of total CO 2 emissions, and this share is expected to increase in the coming decades (UNEP 2020; Grewe et al. 2021).Given the predictable harms of climate change, then, we have a strong reason to refrain from longdistance travel.
Yet people also have good reasons to travel long distances.Some people do so primarily for reasons relating to work or family, but the majority of long-distance flights are conducted for a different reason: leisure. 2 The most important reason for long-distance travel is that it benefits the traveller.Our aim in this paper is to examine the morality of longdistance leisure travel.
The main argument we will examine is the wellbeing argument for long-distance leisure travel ('wellbeing argument', for short).This argument states that the wellbeing benefit to the traveller can provide a sufficiently strong reason to morally justify such travelling.More precisely, the wellbeing argument runs as follows: [P1] If φ-ing provides a significant prudential benefit, i.e. a wellbeing benefit to the agent, there is a morally salient pro tanto reason in favour of φ-ing of the type that can make φ-ing morally permissible.
[P1] Long-distance leisure travel can provide significant prudential benefits.
[P3] The moral reasons against flying are substantial but can be outweighed by prudential reasons.
[C] Therefore, long-distance leisure travel can be morally permissible.
We will defend the wellbeing argument but also argue that it has clear limits.While the prudential benefits of long-distance leisure travel can offer a genuine justification for flying, this justification is riddled with uncertainty.Moreover, it depends heavily on the private judgement of the traveller.Therefore, insofar as prudential benefits can justify long-distance leisure trips, this requires a self-critical stance from the traveller.Furthermore, the more long-distance trips one takes, the more difficult it is to justify another long-distance trip.
This article is structured as follows.First, we set out some assumptions for our discussion of the wellbeing argument and argue that the moral reasons against flying can be outweighed by prudential reasons (Sect.2).We then argue that if φ-ing provides a significant prudential benefit, there is a morally salient pro tanto reason in favour of φ-ing of the type that can make φ-ing morally permissible (Sect.3).Subsequently, we argue that long-distance leisure travel can provide significant prudential benefits according to desire-fulfilment theories of wellbeing, hedonistic theories about wellbeing, and objective list theories about wellbeing.We also highlight two shared features of these theories that are relevant for the wellbeing argument: the uncertainty of the expected prudential value of a trip and the privileged epistemic position of the traveller with respect to assessing this value (Sect.4).We then argue that the wellbeing argument puts a significant burden on travellers to be critical of their own assessments of how beneficial a long-distance trip will be for them. 3Moreover, we argue that the more often a person undertakes long-distance leisure travel, the more difficult it becomes to justify such travel by drawing on the wellbeing argument (Sect.5).Finally, we consider the objection that if the wellbeing argument justifies long-distance leisure travel, it also justifies other extravagant types of polluting consumption, like trips to space (Sect.6).Section 7 concludes.

Preliminary Remarks
Let us start by setting out three assumptions for our discussion of the wellbeing argument.
First, we focus on long-distance leisure trips.There is no fundamental distinction between long-distance leisure travel and other long-distance travel, such as that undertaken for business or family matters.But we focus on leisure travel for two reasons.First, some wellbeing reasons in favour of long-distance travel pertain to leisure travel in particular (see Sect. 4).Second, while long-distance travel for business and family matters may also provide prudential benefits, the motivation for them is typically not uniquely oriented towards the wellbeing of the traveller (but such travel may have significant prudential value too; see Gössling et al. 2019).People may value the relationship with their family in itself, or travel for the wellbeing of their family members.Regarding business travel, the primary benefit is the economic value to the traveller and/or their employer.While the trade-off between economic gains and CO 2 emissions reduction is a significant moral issue, it is quite a different one from the trade-off the leisure traveller faces.Having said that, if the main motivation for business and family-related travel is its prudential value, then the justification of such travel draws on the wellbeing argument and falls within the scope of our discussion.
Second, the term 'long-distance travel' is used in contrast to 'short-distance travel' where long-distance travel is strongly associated with two specific features.First, in most cases, the further away the destination is, the fewer modes of transportation are available to travellers.For example, one could travel from Northern Europe to the Mediterranean by plane, train, car, or perhaps even by bike.But it is less feasible to use these modes of transport when destinations are further away.This is particularly relevant for the wellbeing argument because the moral reasons against long-distance leisure travel are much weaker when it involves these alternative modes of transportation, especially train travel. 4Second, what sets long-distance travel apart from short-distance travel is the remoteness of the location one is headed for.We interpret such remoteness rather broadly.It includes differences in climate, biosphere, and culture.Admittedly, these differences do not necessarily coincide with the short-and long-distance axes.One may travel from London to Victoria and find that Victoria is more similar to London than Marrakesh and Sarajevo, cities that are much closer geographically.However, they are related in this sense: without long-distance travel, the variety of cultures, climates, and biospheres one has access to is limited.
Third, our focus is on the wellbeing of the traveller and not on the wellbeing of other persons.This is not to say that long-distance trips cannot lead to increases in wellbeing for third parties.But we do not discuss this here and exclusively focus on the wellbeing of the traveller.

The Moral Reasons Against Flying
The wellbeing argument says that if flying provides significant prudential benefits to the traveller, there is a morally salient pro tanto reason in favour of flying that can make flying morally permissible.In doing so, it recognizes two sides to the permissibility of flying: prudential reasons in favour of flying and moral reasons against flying.We focus on the first type of reasons, which we examine in the subsequent sections.But to examine the justifiability of flying, we must also consider the third premise of the wellbeing argument, which concerns the moral reasons against flying.
We take it that these are substantial.The most significant reason is that long-distance travel conflicts with individual and collective climate-related duties.5 Climate change will, depending on our collective and individual actions, result in premature human and nonhuman deaths, wreak havoc on people's livelihoods and communities, harm animals and destroy their habitats, lead to a significant reduction in biodiversity, and so forth.However, our individual contribution to climate change is limited and often indirect.Some even argue that our personal emissions do not make any difference and reject the idea that there is a duty to limit our contribution to polluting activities (notably Sinnott-Armstrong 2005). 6 We reject this view.First, it is not clear that we cannot make a difference (Kagan 2011).Flying directly affects the profits of the airline, adds to the profitability of the aviation industry, and incentivizes the airline to provide more flights.Of course, your particular flight will take off with or without you, which limits the short-term impact of refraining from flying.However, the decision not to fly has a chance (though, admittedly, a minor one) of tipping the balance and leading airlines to drop a particular route, resulting in a significant reduction in emissions.While the precise consequences of these actions may be uncertain, the risks involved are also high (Kagan 2011;Broome 2019).Second, the individual duty to contribute to resolving collective problems is plausibly not reducible to the direct consequences of our actions.Such a duty may in fact be heightened because our actions are part of a collective problem (Nefsky 2017;Wieland and van Oeveren 2020).While we cannot do justice to the lively and ongoing debate about collective responsibility and individual duties in collective action problems, we assume here that we have significant moral reasons to limit our unnecessary contribution to greenhouse gas emissions.
How significant are these reasons?A recent estimate shows that the mortality cost of carbon in 2020 is 2.26 × 10 − 4 lives per ton (Bressler 2021).This translates into roughly 4.3 deaths per 10,000 individual long-distance trips from Paris to New York. 7This may not appear to be many, but if we compare this to the expected deaths from drunk driving, which is 4 × 10 − 6 deaths per 100 miles driven, 8 taking one long-distance flight and driving drunk for 10,000 miles are equally harmful.Moreover, the number of expected deaths by passive smoking caused by someone who smokes for 24 years is about 0.019.This approximates to taking two long-haul flights per year for 24 years (Yousuf et al. 2020).These comparisons leave out many significant factors, such as the environmental costs of driving and harms not related to human deaths.Flying constitutes significant harm and imposes lethal risks on others, even if those risks are indirect and small.This contribution to the untimely deaths of others provides us with a substantial moral reason against flying.At the same time, the fact that the harm to others is relatively small and that the risk is relatively low (depending on one's understanding of the available statistics) limits the wrongness of flying.
There has been a fierce debate about the moral salience of such assessments (see Hiller 2011; Broome 2012Broome , 2019;;Fragnière 2018;Hickey 2021;Stefansson 2022).Fragnière (2018) has recently argued that while we have strong moral reasons to avoid harm, we cannot equate the average harm of climate change to more direct harms.Building on Nolt's (2011) estimate, he argues: "From an individual point of view, being responsible for the death of two persons seems indeed far worse than being responsible for one two-billionth of each death, which in this case amounts to shortening the life of each victim by 0.6 seconds" (p.656; cf.Hickey 2021).We cannot do justice to this debate fully and acknowledge that it is difficult to provide an estimate of the strength of the reason to avoid polluting activities with precision and confidence.What matters for our argument is that emitting greenhouse gases is the type of action one has good moral reason to avoid but which may be outweighed by other concerns that have significant value.Notably, Fragnière (2018, p.660) comes to a similar conclusion.
Finally, someone might think that there is no or only a minor moral reason against flying if one offsets one's emissions.Broome (2012;see Hyams and Fawcett 2013 for a discussion), for example, argues that by completely offsetting your emissions, you cause "no greenhouse gas to be added to the atmosphere.You therefore do no harm to anyone through your emissions" (p.87; see also MacAskill 2015; p.174).We want to make two points about offsetting that are relevant for our discussion, though we acknowledge that the issue of offsetting is complex and fiercely debated.First, there is empirical uncertainty about the extent to which offsetting can fulfil Broome's requirement of reaching net zero emissions.For example, planting trees and many other carbon dioxide removal methods are imperfect and uncertain substitutes for emissions reductions given possible leakage, including albedo change and wildfires, and broader ethical issues, such as local people's rights (Hyams and Fawcett 2013, pp. 93-94).Moreover, Orri Stefanson (2022) has recently argued that because of the time difference between the emitting acts and offsetting, it is highly unlikely that offsetting ever prevents the harm resulting from emitting acts, which is what Broome thinks.Second, if future generations are significantly benefitted by planting trees or some other form of offsetting, we may have strong reasons to do so.However, previous actions that benefit future people cannot offer a justification for harmful actions.Volunteering as a road safety volunteer does not justify reckless driving.A rich person may offset 100 tons of carbon by planting a forest, but this does not justify careless emissions (such as putting heaters on outside, just for fun).This is not to say that offsetting can make no moral difference.But it does not excuse us from requiring a justification when we engage in polluting consumption.

Prudential Value and Moral Significance
Does long-distance leisure travel provide prudential benefits?That is, does it provide wellbeing benefits to the traveller?If so, is there a morally salient pro tanto reason in favour of such trips that renders long-distance leisure travel morally permissible?
For utilitarian and other welfarist consequentialist views, prudential benefits play a direct role in determining whether an action is morally permissible, mandatory, or prohibited.From such perspectives, prudential benefits are wellbeing benefits and are therefore morally salient.However, many ethicists reject such views as overly restrictive.Wellbeing harms and benefits may matter, but they are not all that matters from a moral point of view.Typically, non-consequentialists will maintain that welfare consequentialism gives wellbeing benefits too much weight.In particular, they might be sceptical about the moral weight of prudential benefits.If Alice has a good moral reason to refrain from φ-ing, the prudential benefit Alice gets from φ-ing will not easily make it permissible for Alice to φ.
On the other hand, the idea that prudential benefits have no bearing on the moral permissibility of an action is implausible.We can distinguish between moral reasons and morally relevant reasons.Moral reasons are reasons that can imply that individuals are morally required to act in a certain way (see, in particular, Portmore 2008).Prudential reasons are typically not moral reasons but morally relevant reasons.It can be tremendously beneficial for someone to attend a yoga class, but that does not mean that doing so is morally required (though consequentialists may see this differently).The wellbeing benefits of flying would be this type of benefit, which constitutes morally relevant reasons but not moral reasons.
An important objection to the first premise of the wellbeing argument -if φ-ing provides a significant prudential benefit, there is a morally salient pro tanto reason in favour of φ-ing of the type that can make φ-ing morally permissible -is that moral reasons always override non-moral reasons, including morally relevant reasons.Recently, Jean Kazez (but see also Singer 1977;2018) draws on a variation of this premise to suggest that the taste of meat can at least in principle make a moral difference to the permissibility of eating meat.If the taste of meat provides significant prudential benefits, this supports the claim that killing animals is permissible.
In response, Andrew (2020) argues "that moral reasons, by their nature, are peremptory, and so override nonmoral reasons" (153).Such a strong view, however, is highly demanding.It implies that our moral reasons to act should not be informed by the consequences of the actions we take for our own wellbeing.But this seems too strong.Consider the following example put forward by Portmore (2008), which is meant to show that non-moral reasons (and in particular prudential reasons) may not constitute moral requirements but do have the power to make actions permissible that would otherwise be impermissible.Donating one's downpayment.If person P can donate a significant sum of money from a wealthy corporation to an effective charity with no costs to themselves, this might be morally required.However, P is not morally required to donate the sum of their mortgage down payment to an effective charity (2008, pp. 372-373).
If Andrew is right, it is morally impermissible to use money for down payments if there are moral reasons to spend such money in other ways.This is clearly too strong, so prudential reasons must carry some moral weight.This is true even if there are strong moral reasons against acting on these prudential reasons.We follow Portmore in this respect in the remainder of this article.The presence of prudential reasons, such as prudential reasons for longdistance flying, can make otherwise impermissible actions permissible.That is, the moral reasons against long-distance leisure travel can be outweighed by the prudential reasons in favour of such trips.
However, we must consider three other objections to the claim that prudential benefits provide morally salient pro tanto reasons in favour of polluting actions, namely that negative duties override prudential benefits (Sect.3.1), that prudential benefits must meet a minimal threshold to carry moral weight (Sect.3.2), and that this leaves no room for fairness considerations (Sect.3.3).Let us discuss these in turn.

Are Negative Duties Not to Pollute Overriding?
Duties to limit one's emissions are typically seen as negative duties, that is, as duties not to harm others.9As we have argued above, prudential reasons may outweigh moral reasons based on positive duties -such as duties to donate to charities that alleviate suffering.However, positive moral duties are plausibly more easily outweighed by prudential concerns than negative duties (Hiller 2011).Can negative duties still be outweighed by prudential concerns?
In contemporary societies, many behaviours contribute, perhaps very indirectly, to suffering that is almost impossible to avoid entirely.Fuel consumption is the most prominent example of this (Lichtenberg 2010).We may attempt to avoid polluting behaviours but doing so is something we can only do in a limited way.This illustrates an important similarity between our negative duty not to pollute and our positive duty to contribute to the alleviation of suffering.We may imagine, for instance, that the person buying a house in Portmore's example could spend the down payment on installing a fossil fuel-free heating system in her old house, limiting her contribution to climate change.Just as it seems unreasonable to say that donating one's money can result in a moral requirement independent of prudential concerns, it also seems unreasonable to say that limiting one's harm to others results in a moral requirement independent of prudential concerns.Strong prudential benefits can sometimes outweigh both positive and negative duties.In fact, perhaps there is a way to donate the down payment to limiting pollutions elsewhere, which might make a larger overall contribution to limiting climate change than installing the fossil fuel-free heating system.While our reasons to avoid emissions may be stronger than our reasons to prevent them elsewhere, the similarity between these cases in this context makes it unlikely that their moral salience is categorically different.

Prudential Concerns as Trivial Concerns
One might object to the wellbeing argument that prudential benefits must meet a minimal threshold to carry moral weight. 10If it comes to one's health, one's survival, or being able to buy a house, prudential concerns may have sufficient weight to render otherwise impermissible actions permissible.But the prudential value of long-distance leisure travel may only be trivial and may be insufficient to justify such trips on the basis of the wellbeing argument.
Though we are sympathetic to the spirit of this objection -it suggests, for example, that carefully weighing prudential value and other types of value is necessary -we believe the idea that long-distance leisure travel merely provides trivial prudential benefits must be rejected.First, long-distance leisure trips are not as trivial as they may appear to be to some people.Many travellers go to great lengths to find time and money for such trips.They constitute the most common item on bucket lists (Periyakoil et al. 2018;Zascerinska et al. 2022).A flight's distance is positively correlated to the perceived importance of that trip by the traveller, which holds particularly for someone's first intercontinental flight (Gössling et al. 2019).Moreover, both travellers and leisure researchers describe and consider longdistance leisure trips as highly meaningful experiences (Bosangit et al. 2015).Of course, travellers may overestimate the value and meaning of their trips, but even so, it is not obvious that long-distance travel only has trivial value.
Second, we agree that non-weighty prudential concerns do not match weighty moral concerns.However, many moral questions are not particularly weighty.For example, we may have moral reasons to buy a more sustainably grown cucumber rather than a less sustainable one, and we may have a moral reason to apologize to our neighbours for continuing our noisy party a little later than promised.In such cases, it seems that self-interested concerns that are not particularly weighty still have relevance, such as that sustainable cucumbers taste utterly revolting or that noisy parties are fun.Put differently, even if prudential concerns must meet a threshold to qualify as non-trivial, this threshold needs to be low to avoid implausible consequences.And at least in some cases, long-distance leisure travel provides non-trivial prudential benefits.

Prudential Concerns and Fairness
The wellbeing argument may appear to neglect fairness considerations, which is potentially confusing.Air travel is conducted in a highly unequal manner.For example, estimates from the UK show that "on average between 2006 and 2017/8, only 20% of households are responsible for 76% of all flights, 10% of households for 51%, and 1% for 10% of flights" (Büchs and Mattioli 2021, p. 95).Büchs and Mattioli (2021) found that flying frequently strongly correlates positively to income.The wellbeing argument ignores this.It states, for example, that if flying provides a prudential benefit, there is a pro tanto reason in favour of flying.But it does not state that such prudential benefits only have moral weight if, say, the agent has never flown before or has flown comparatively few times.
We agree that the wellbeing argument should be responsive to such fairness concerns.We believe that the prudential value of long-distance leisure travel can be equally high for both the most well-off and the worst-off.But the wellbeing argument can incorporate egalitarian (or prioritarian) concerns by accounting for the distribution of wellbeing benefits and burdens, which would imply that the value of additional prudential benefits plausibly decreases as someone is comparatively better off (Parfit 1998).All other things being equal, the moral weight of an equal prudential benefit is greater for people with lower wellbeing levels and lower for people with higher wellbeing levels (see also Sect.5).The wellbeing argument, therefore, can capture the discomfort about travel-related inequalities that the fairness objection brings to the fore.
In the remainder of this article, we discuss how the prudential benefits of long-distance leisure travel must be assessed and weighed against the moral reasons against such trips.For that purpose, we examine the nature of wellbeing and consider the second premise of the wellbeing argument next, which states that long-distance leisure travel can provide significant prudential benefits.

Long-distance Leisure Travel and Prudential Value
Wellbeing describes what makes life good for the person who is living that life, that is, good for their sake (Tiberius 2015).Many goods contribute to wellbeing.Eating an ice cream on a sunny afternoon may be good for me.But eating ice cream is not in itself a wellbeing good.After all, eating ice cream against our will or without deriving any pleasure from it does not contribute to our wellbeing.To the extent that eating ice cream is good for someone, it is good because it is, for example, pleasurable or fulfils a desire.Theories of wellbeing describe what is non-derivatively good for us.
Let us recall the second premise of the wellbeing argument: long-distance leisure travel can provide significant prudential benefits.To justify a particular action by drawing on its prudential value, we must assess its prudential benefits vis-à-vis the prudential benefits of other actions.For example, a long-distance trip may have prudential value, but if a shortdistance trip is equally valuable but less harmful, the prudential value of long-distance leisure travel does not justify the long-distance trip, all other things being equal.
In this section, we first examine how three dominant theories of wellbeing -desire-fulfilment theory, hedonism, and objective list theories -assess the value of long-distance leisure travel.We then discuss two features shared by these theories that are relevant for the wellbeing argument, namely the uncertainty of the expected prudential value of a long-distance leisure trip and the epistemic position of the traveller with respect to assessing this value.

Desire-fulfilment Theory of Wellbeing
According to the desire-fulfilment theory of wellbeing, wellbeing is constituted by the fulfilment of desires.What is non-derivatively good for people is the fulfilment of their desires; what is bad for them is the frustration of their desires. 11In other words, it is because a person desires φ that having or doing φ contributes to their wellbeing.Moreover, desire-fulfilment theories maintain that the stronger the desire for φ, the better φ is for the individual.
Desire-fulfilment theory has a straightforward answer to the question of whether longdistance leisure travel contributes to wellbeing.People desire long-distance vacations.Therefore, long-distance travel contributes to wellbeing.Put differently: Prudential Value of Flying for the desire-satisfaction Theorist.A long-distance leisure trip is good for person P to the extent that P desires (particular features of) the trip.
It seems that long-distance leisure travel frequently provides opportunities for satisfying one's desires, over and above alternatives.The desire for long-distance trips seems high, as indicated by the willingness to pay for such trips, which are comparatively expensive.And as previously mentioned, long-distance travel frequently appears on people's bucket lists, which indicates how central this desire is for people.
However, we must consider two important caveats.The first is that many desire theorists acknowledge that certain desires seem irrelevant to wellbeing.Parfit (1984) gives the example of a stranger on the train that you will never see again.You may desire that their endeavours will be successful.But their success (or failure) does not affect your wellbeing.Other desires seem harmful if fulfilled, such as a desire for a heroin shot.Many desire theories therefore maintain that morally relevant desires are only those desires that are rational, informed, and self-interested.This qualification is important because not all desires that can be satisfied by long-distance leisure travel may meet these standards.For example, travellers may be overly optimistic regarding their expectations of a trip and their desire may be influenced by misleading advertisements.Long-distance leisure travel can be romanticized (perhaps also as a result of advertisements or social media depictions of such trips), and the reality may disappoint (Gössling et al. 2019).Such desires, then, are not fully informed desires, which many desire theorists would see as detracting from their wellbeing value.
The second caveat is that, for the purposes of practical ethics, it is difficult to measure levels of desire-satisfaction in a way that is interpersonally comparable (Hausman 1995;List 2003;Rossi 2014; but see also van der Deijl 2018 in the context of actual economic welfare measures).For example, while many people are willing to pay significant sums of money for such trips, people who undertake them tend to be wealthier, making such figures difficult to compare.We return to this below.

Hedonism
According to hedonism, wellbeing is constituted by pleasure (or enjoyment) and pain (or suffering) (Mill 1871;Sidgwick 1907;Crisp 2006; Bramble 2016). 12We can define the hedonist stance towards the prudential value of long-distance leisure travel as follows: Prudential Value of Flying for the Hedonist.Long-distance leisure travel is good for person P to the extent that it positively affects P's hedonic level.
Long-distance leisure travel is often associated with enjoyment.It commonly involves a variety of enjoyable activities and can lead to significant reductions in stress.Yet the available empirical evidence is at best mixed on whether long-distance travel leads to more enjoyment than vacations closer to home.While the impact of holidays on happiness in general is significant, it is also short-lived (Nawijn 2010).Moreover, distance only plays a minor role in our enjoyment of vacations (Nawijn 2011;but see Gössling et al. 2019).There is little evidence that vacations closer to home have a different effect on hedonic levels than vacations further away (De Bloom et al. 2017).This particularly matters, of course, if we consider the reasons in favour of long-distance travel compared to those for short-distance travel in light of the moral reasons against flying, such as its impact on climate change.
Hedonism is often understood as a unidimensional theory that imagines the quantity of pleasure and the quantity of pain on the same scale (that is, more pain implies less pleasure, and less pleasure implies more pain).On such a view, long-distance leisure travel is beneficial but may not be more beneficial than other leisure trips.However, some hedonist views, such as Mill's qualitative hedonism, deviate from this picture.On Mills' view, for example, the quality of pleasure itself matters to wellbeing, independently of its quantity (cf.Schmidt-Petri 2003;Fletcher 2008). 13Recently, Bramble ( 2016) has defended a version of hedonism in which pleasurable experiences only count to the extent that they are novel experiences.Such deviations from the common interpretation of hedonism are notable for our purposes.Long-distance leisure travel typically provides a context in which people can experience novel cultures and opportunities, environments, food, and drink, among other things.Insofar as particular experiences are qualitatively superior to others, for instance due to their novelty, long-distance travel may be a unique context in which to experience certain high-quality pleasures, but only insofar as long-distance trips actually contain these goods.The studies mentioned above may underestimate the prudential benefits of such trips.At the same time, such more complex hedonist theories make it more difficult to quantify such judgements, let alone measure them in concrete contexts.
For both the unidimensional and the qualitative types of hedonism, however, the possible prudential benefits of long-distance leisure travel are plausibly quite person-relative.Some people enjoy long-distance leisure travel more than others, for some people long-distance travel will be more stressful than for others, and so forth.Moreover, the extent to which a long-distance trip constitutes a novel pleasure obviously depends on the history of the traveller and their openness to novel experiences.
To sum up, for unidimensional hedonistic theories, the prudential benefit of long-distance leisure travel is not evidently comparatively higher than that of short-distance leisure travel.According to sophisticated hedonistic theories, the benefits of long-distance leisure travel may be significant, but the value of these is difficult to quantify in specific contexts.In either case, hedonic benefits are plausibly highly person-relative.

Objective List Theories
According to objective list theories of wellbeing, wellbeing is constituted of a plurality of goods that are independent of our attitude towards these goods. 14This could include goods like knowledge, friendship, development of certain abilities, and so forth (Fletcher 2015).The wellbeing of a person is a function of their possession of these goods.Hence, such theories will say the following about long-distance leisure travel: Prudential Value of Flying for the Objective list Theorist.Long-distance leisure travel is good for person P to the extent that it contains or gives P access to goods that are objectively good.
For objective list theories, then, insofar as long-distance leisure travel is good, it is good because it is pleasurable, interesting, a personal achievement, a contribution to knowledge, etc.
Having said this, objective list theories can ascribe value to long-distance leisure travel on different grounds.The reduction in stress it produces may improve our (mental) health, we may expand our knowledge of the world in ways which we are unable to do from home, and we may appreciate aesthetic values we would not otherwise experience.We may connect to nature (or, as Nussbaum 2011 puts it, our relationship to "other species") in ways we otherwise could not do.Like hedonists, objective list theorists may take the novelty of long-distance travel to be an important contributor to its value: experiencing a culture or an environment we have not experienced before may teach us something we would otherwise not learn.Going somewhere for the first time may be an achievement and a way to exercise and develop our human capacities.This illustrates that there are several ways in which objective list theorists can ascribe value to long-distance leisure trips.
A widely recognized problem for objective list theories is their difficulty with making overall comparative judgements.Long-distance travel may benefit the traveller, but it is not evident how significant these benefits really are.Consequently, for our purposes, it can be difficult to assess to what extent they outweigh reasons against flying.First of all, it can it be difficult to quantify certain wellbeing goods, such as knowledge and achievement.How much knowledge does one acquire by visiting a remote temple complex?But there is also a deeper axiological uncertainty about how the comparative value of these goods vis-à-vis other goods, and, as a result, about the value of long-distance leisure trips relative to other activities (which may, for example, have a smaller impact on climate change).Objective lists typically do not have the tools to make such comparative judgements (cf.Sen 1985; Lin 2014).

Taking Stock: Uncertainty and Privacy
We can make three observations from the discussion of long-distance leisure travel in relation to desire-fulfilment theories, hedonism, and objective list theories of wellbeing.The first is that long-distance leisure travel provides access to a variety of wellbeing goods.For some of these goods, such as novel experiences and pleasures, the fulfilment of lifelong desires, and learning about cultures you would otherwise not learn about, long-distance leisure travel arguably provides a privileged if not unique context in which to obtain these goods vis-à-vis short-distance alternatives.For that reason, we consider the second premise of the wellbeing argument, that long-distance leisure travel can provide significant prudential benefits, to be a plausible claim.At least in some cases, flying can provide significant prudential benefits that one could not obtain otherwise.
But we need to make two further observations, both of which put pressure on the idea that the wellbeing argument simply justifies long-distance leisure travel.These observations hold across the different wellbeing theories and concern the uncertainty about the actual wellbeing benefits for someone contemplating a long-distance leisure trip and, moreover, that these benefits depend to a significant extent on the private assessment of the traveller.We address these in turn.

Uncertainty About the Value of the Trip
The different theories of wellbeing all recognize the uncertainty about the wellbeing good at stake: we do not know what a trip will be like, and so we do not know exactly what prudential value can be derived from it.Because long-distance trips typically involve novel experiences, this makes them unpredictable.We may have imagined the trip quite differently from what it turns out to be like.Even if we know which particular goods constitute wellbeing, this uncertainty makes it difficult to assess the prudential value of such a trip in advance.For example, a trip may not be as enjoyable or educational as we thought it would be.Importantly, this is not a contingent fact about long-distance travel but part of the very reason we have to value long-distance leisure travel: its remoteness from what we know.Exactly because long-distance travel involves a wide variety of novel experiences, it is difficult to assess its prudential value in advance (see also Paul 2015).

Privacy
The assessment of the prudential benefits of flying relies significantly on private judgements.These benefits are person-relative, and the traveller is epistemically privileged with regard to what is prudentially valuable for them.Not everyone will equally enjoy, desire, or learn from a long-distance leisure trip.But knowledge about someone's particular characteristics in this sense are highly private.They are (or are closely linked to) our mental states, such as our desires, curiosities, and tastes, and things we tend to enjoy.Yet our mental states are opaque to others and may even be misjudged by people who have a close relationship with us, such as our loved ones.Therefore, the prudential benefit of a long-distance leisure trip depends on facts that are difficult for people other than the traveller to assess.This is not to say that people are always better at judging their own mental states, and, consequently, the likely prudential benefits of certain activities than others (Haybron 2007;Schwitzgebel 2008).Eric Schwitzgebel gives the example of a spouse who is more aware that their partner is angry than the partner themself.This is an example of an occurrent mental state (what is a person experiencing right now?), but the same holds for our more general make-up (how will someone experience something in a given context?).A parent of an introverted child may realize better than their child that they will not enjoy their backpacking trip as much as they think they will, not only because the parent has a more realistic picture of what the trip will be like, but also because they know their child well and can see that the child is being too optimistic about how much they will like the trip.However, these examples illustrate our point.The type of intricate knowledge about an individual that is required to assess how they will enjoy, learn from, and desire something is almost always most accessible for the traveller themselves.Hence, the traveller is epistemically privileged when it comes to assessing the possible prudential benefits of long-distance leisure travel.

Ethical Implications
In Sects.2-4, we have defended the three premises of the wellbeing argument.In short, we have argued that long-distance leisure travel can provide significant prudential benefits, which means that prospective travellers have a morally salient pro tanto reason in favour of flying.If the traveller has good reasons to believe that significant prudential benefits will obtain from long-distance leisure travel, the wellbeing benefits such leisure travel confers on the traveller can justify flying.Whether these wellbeing benefits outweigh the reasons against long-distance leisure travel not only depends on the seriousness of the moral reasons against flying but also on the size of the wellbeing benefits at stake.While these judgements are highly contextual and allow for reasoned disagreement and epistemic uncertainty, we will defend two claims about the practical implications of the wellbeing argument.First, the wellbeing argument puts a significant burden on the agent to be critical of their own assessments of how beneficial a long-distance trip will be for them.Second, the wellbeing argument suggests that the more often a person undertakes long-distance leisure travel, the more difficult it becomes to justify such travel.We will now consider both implications of the wellbeing argument.

Private Judgement
The wellbeing argument maintains that the prudential benefits of long-distance leisure travel offer a pro tanto moral reason to fly.Yet the size of these benefits is difficult to establish.Because the benefits of long-distance leisure travel, and the accompanied flying, are more difficult to determine and more private than other cases in which primarily prudential value is at stake, the wellbeing argument risks being overly permissive.A person may earnestly justify their trip by saying "I think this trip will be good for me".However, as we argued above, both the features of the trip and the wellbeing benefits for the traveller are uncertain.A justification like this requires that one has good reason to believe that flying is in fact permissible, which requires having a good sense of the benefits of the trip.It is possible, and even tempting, to be overly optimistic about a trip beforehand.Yet the wellbeing argument requires a genuinely critical stance from the traveller.This is because the traveller is not only the person who needs to decide whether or not to take a long-distance leisure trip but is also the person who is in the best position to evaluate the expected wellbeing benefits.This puts an important responsibility on the agent to make this judgement genuinely and fairly.
This point is particularly relevant in light of the fact that the person deciding whether or not to take a long-distance leisure trip has a relevant stake in that decision.Let us assume that it is clear that the long-distance trip will have some wellbeing benefits for person P, but the extent of these benefits is not clear.Also assume that P is genuinely committed to making an ethically justifiable choice, with the wellbeing argument in mind.Because of the uncertainty involved, the epistemic circumstances leave a lot of space for judgement.This gives P a prudential reason, or an incentive, to be as optimistic as possible about the wellbeing benefits.If P judges the trip to be very good, and in fact it is good, they have justifiably gone on a good trip.If P judges it to be better than it actually turns out to be, P still benefits, even though they have to recognize that in hindsight it was an ethically undesirable choice.If P is too pessimistic, they will have to conclude that they should not go on the trip, even though this trip will benefit them.
The epistemic judgement a traveller needs to make thus involves an internal conflict of interest.A commitment to the wellbeing argument requires that travellers make a fair assessment of the prudential benefits of taking a long-distance leisure trip.But in light of this very commitment, they have an incentive to be optimistic when making this judgement.This puts an important responsibility on travellers.Insofar as they can justify long-distance trips through the wellbeing argument, it requires them to look critically at their own assessment of how good the trip will be for them.

Frequent Flyers
A second moral implication of our analysis is that the wellbeing argument is unlikely to render long-distance leisure trips by frequent flyers permissible.The more frequently a person takes long-distance leisure trips, the more difficult it is to justify such trips by drawing on prudential benefits.There are three arguments for this: an argument concerning the decreasing marginal returns of flying for wellbeing, an egalitarian argument, and an argument about fairness regarding contributions to climate change.
Consider first the argument concerning the decreasing marginal returns of long-distance leisure travel for wellbeing.This is most evident for goods that inherently depend on the novelty of the travel experience.The second time one travels to a faraway destination, one will probably not learn as much or experience as much novel enjoyment as the first time.Moreover, people's desire for the goods in long-distance travel is plausibly subject to marginally decreasing returns, like almost any other consumer goods.The same is true for its contribution to our happiness.In short, there seems to be declining marginal utility in terms of prudential value to additional long-distance leisure trips the more frequently a person embarks upon such trips.The more frequently a person goes on long-distance trips, the less they contribute to their wellbeing.
While this seems intuitive, it is important to note that such declining marginal benefits of long-distance travel for wellbeing are not self-evident, at least not for all goods deriving from long-distance leisure travel.There may be goods regarding which the prudential benefits increase as a person travels more frequently.There is some evidence that this is true for cultural goods, such as museum visits (Alderighi and Lorenzini 2012).Moreover, Elster (1986) theorizes that activities that are part of self-realization projects, such as learning to play a musical instrument, typically have marginally increasing benefits.Long-distance travel could very well be like this, in which case this counts against the marginal utility argument.However, the available evidence indicates that long-distance leisure trips are more like typical consumer goods.Kroesen and Handy (2014), for instance, find that the relationship between holiday trips and subjective evaluations of enjoyment and satisfaction is concave, indicating marginal returns from holiday trips for (different components or conceptualizations) of happiness.
The second and third arguments for why the wellbeing argument is unlikely to support prudential arguments for long-distance leisure trips by frequent flyers do not concern the prudential benefits at stake but how such benefits must be weighed against other moral concerns.The second argument is that insofar as long-distance trips are a significant benefit to individuals, they are also subject to fairness concerns.Wellbeing benefits have significant moral value, but such value is particularly morally significant for those who are comparatively worse off.For that reason, it may seem easier to justify the trip of an underprivileged person, who otherwise lacks access to the goods that can be obtained during such a trip, than for a privileged person who has already experienced many of these goods, even if both would benefit equally from the trip.If fairness in the distribution of wellbeing benefits has moral significance, prudential benefits have more moral weight for travellers who are comparatively worse off.
The third argument for why the wellbeing argument is unlikely to support prudential arguments for long-distance leisure trips by frequent flyers is that just as legitimate fairness concerns exist with respect to the benefits of flying, they plausibly also exist for the environmental costs of flying.Consumption-related CO 2 emissions are distributed highly unequally.A recent Oxfam report estimated that the emissions of the richest 1% are double the emissions of the world's poorest half (Gore 2020).The very fact that choices cause so much (unnecessary) climate damage makes it more difficult to justify further polluting behaviour, even if we take the wellbeing benefits associated with this long-distance leisure travel seriously.As Dale Jamieson, for example, puts it, "those of us who are rich by global standards and benefit from excess emissions have strenuous duties in our roles as citizens, consumers, producers, and so on to reduce our emissions and to finance adaptation". 15In light of this, long-distance trips by people who have not yet been responsible for much polluting consumption seem more justifiable than those by people who have already been responsible for a lot of polluting behaviour. 16And for that reason, frequent flyers will have a harder time justifying additional long-distance leisure travel via the wellbeing argument than non-frequent flyers.

Objection: The Benefits of Space Travel
We have argued that long-distance leisure travel can be justified through the wellbeing benefits it provides the traveller with.But does this also justify much more polluting activities, such as trips to space, on the ground that they provide significant wellbeing goods that one may not be able to obtain elsewhere?
While this line of reasoning is analogous to the wellbeing argument for long-distance leisure travel, the wellbeing argument for leisure space travel is limited by a number of important factors.First, space travel is significantly more polluting, creating roughly 50 tons of carbon per passenger, 25 times those of a long-distance flight (Gammon 2021).Secondly, those who can undertake such trips are among the wealthiest in the world.If the wellbeing argument is sensitive to egalitarian concerns, as we have argued it should be, benefits for those who are already so well-off, even if those benefits are significant, should have very little moral weight.So even if the wellbeing argument can justify taking some long-distance flights, it cannot plausibly justify space trips.

Conclusion
In this paper, we have examined the extent to which individuals can justify long-distance leisure travel by saying that it increases their wellbeing.In particular, we have examined the wellbeing argument, which states that because of its prudential value, long-distance leisure travel can be morally permissible if the benefits are sufficiently weighty.
If our argument is correct, the prudential benefits provided to travellers can have moral weight and long-distance leisure trips can significantly increase their wellbeing according to three common theories of wellbeing.Hence, it is possible that long-distance leisure trips can be justified because they are good for us.However, the wellbeing argument requires an epistemic judgement in which the traveller has the most reliable access to knowledge about the expected prudential value resulting from such trips and in which they have a significant stake.This puts an important moral responsibility on the traveller to look critically and fairly at the prudential benefits of a trip.Moreover, insofar as the wellbeing argument can justify taking long-distance leisure trips, this justification becomes increasingly weaker the more long-distance trips a traveller has made.