• Daniel Sharp

Does COVID-19 Justify Travel Bans?



One of the first measures states took in response the outbreak of COVID-19 was restricting international mobility. By mid-2020, every country in the world had issued some form of special travel restrictions. Some of these restrictions have eased overtime. Yet, many countries remain effectively closed. Travel to the United States of non-citizens remains largely banned, unless one is explicitly exempted. Travel to Taiwan and New Zealand is virtually impossible for non-nationals. Many remain families remain separated due to these restrictions. How should we think, ethically, about these kinds of restrictions?


The question I’ll focus on is whether and when it is permissible for states to ban entry in order to prevent the spread of coronavirus. Entry bans aren’t the only kind of travel restrictions that states have implemented. States have imposed various conditions on entry, like testing and quarantine requirements. Yet, banning entry is harder to justify than conditioning entry and imposing mask, testing, and quarantine requirements on travelers; the latter restrictions are often clearly justified.


My question is whether entry bans are morally permissible. Before broaching this question, a digression is required. There are different views about whether states may control entry into their territories, and how one views the morality of border control in general might seem to determine one’s answer to my question. According to one position, states have considerable discretion over whom they admit. They possess, perhaps on grounds of collective self-determination, a right to exclude any non-national from entering, with the exception of those seeking asylum. According to a second position, borders should, in general, be open and people free to move across them because freedom of movement is a human right. States may deny entry only under extreme circumstances.


The effectiveness of travel restrictions [...] has much to do with the dynamics of the outbreak in the banning country and in the countries against which such bans are directed.

It might seem that answering the question ‘may states permissibly ban entry to prevent the spread of COVID-19’ is straightforward: if one endorses the former view, then states may ban entry in order to stem the spread of COVID-19, for they are generally entitled to impose whatever entry restrictions they like; if one endorses the latter view, then states may likely not ban entry to stem the spread of COVID-19, for to do so would arguably infringe on the mobility rights of would-be border crossers.

Yet, this inference is too hasty, as I argue in a forthcoming piece. On the one hand, the view that states have a right to exclude is a view about the state’s authority to set its own entry policies. But even if one believes that a state possesses the authority to regulate their borders, and so other states (e.g.) may not interfere with its decisions on these matters, this does not settle the question of how that authority ought to be exercised. Suppose I promised you that I would have you over for dinner on Thursday. When you show up at my door on Thursday, I refuse you entry, for no good reason. I have the authority to do this. But I nevertheless act wrongly when, in breach of my promise and without excuse, I slam the door in your face. Since having the authority to exclude does not settle how that authority out to be exercised, the right to exclude does not settle whether states are morally permitted to exclude.


On the other hand, defenses of the right to freedom of movement bear more directly on the permissibility of entry restrictions, for they identify certain weighty interests people have in being able to move freely across borders. Yet, defenders of freedom of movement are not absolutists. True, the right to freely move yields a strong presumption in favor of permitting cross-border mobility: after all, significant interests are bound up with international freedom of movement. But this presumption, they believe, is defeasible. Thus, defenders of a right to freedom of movement acknowledge that it may sometimes be restricted.


The key question, then, for both defenders of the right to immigrate and defenders of the right to exclude, is under what conditions the case for restrictions suffices to defeat the presumption in favor of mobility. Here, one might reasonably disagree about how much weight should be given this presumption. But it seems to me very likely that both defenders of the right to exclude and of the human right to move could agree that this presumption can be overcome when the best available empirical evidence indicates that: (1) international mobility of a certain kind credibly is likely to cause significant harm to residents, (2) restrictions on international mobility would likely prevent or significantly reduce that harm, (3) such harm cannot be prevented through less constraining measures, and (4) the costs of adopting such restrictions measures are not themselves comparable to the costs such measures aim to prevent. When these conditions are met, states can justify their restrictions to those excluded by them: they can say the costs of such restrictions on would-be travelers are fair for them to bear because only by adopting such measures can they prevent significant harms to residents.


[D]espite the scaremongering of politicians, COVID-19 is not an immigration problem; it’s merely that people can spread viruses, and mobility, intra- or international, spreads people.

Do actual entry bans in response to COVID-19 meet these conditions? The case for condition (1) is clear enough. COVID-19 can cause, unless met by reasonable preventive health measures, significant harms. It can overwhelm health care systems and cause significant morbidity; it can disrupt social and economic life. International mobility, moreover, is one factor in its transmission. It was especially relevant in the outbreak of the pandemic, allowing the virus to reach new areas. International mobility can also play a role in the spread of new variants, as it has with Delta. So, condition (1) is likely met.


Here, it should be emphasized, however, that there’s nothing special about state borders. It’s not that international travels are, in principle, any more likely to contribute to the spread of COVID-19 than domestic travels—despite the scaremongering of politicians, COVID-19 is not an immigration problem; it’s merely that people can spread viruses, and mobility, intra- or international, spreads people.


The case for condition (2) is also, in many cases, relatively strong, albeit matters are more complicated. Curbing mobility, whether local, national, or international, can help curb COVID-19 transmission. Indeed, there’s some evidence that entry bans, especially when combined with other public health interventions, can significantly dam the spread of COVID. Travel restriction and lockdown measures within China at the beginning of the pandemic “averted 70.5% of exported cases in China and doubling time was increased from 2 to 4 days.” Similarly, modeling studies indicate that Australia’s ban on travel from China “was effective in delaying widespread transmission of COVID-19” reducing case importation between January 31st and March 2 by approximately 79%. Another study of Australia’s ban found similar results.


The effectiveness of travel restrictions, it should be emphasized, has much to do with the dynamics of the outbreak in the banning country and in the countries against which such bans are directed. The Australian studies concern bans directed at a single high-incidence country, implemented after COVID-19 had already been locally imported. There’s little evidence that full or partial travel bans make much difference when implemented against low-incidence states or by high-incidence states.


Moreover, the authors of the above studies emphasize that the effect of travel bans diminishes sharply in absence of lockdown, social distancing, masking, and other public health measures to reduce the spread of COVID-19 once it is present locally at a significant level. Banning travel, but doing little or nothing stem of the virus domestically, they conclude, is an ineffective strategy, as local case replication will outstrip international case importation within a short period of time. The United States learned this the hard way under the Trump administration, boasting the highest caseloads in the word despite maintaining significant travel restrictions.


To be sure, certain states have been able to employ zero-COVID strategies, which rely heavily on travel bans combined with other public health measures. New Zealand, Taiwan and the Canadian province of Newfoundland and Labrador have all employed such strategies, with relative success. However, this kind of strategy seems most effective when implemented early, before the virus arrives, or once the state has a zero or near-zero COVID incidence. This model is thus inapplicable to the majority of states.


[W]hile entry bans for nonessential travel are often justified, justifying the use of such bans to exclude immigrants is much harder; excluding those in dire need of protection is almost always impermissible[.]

In sum, entry bans sometimes meet condition (2), although much depends on the specifics of the ban in question, the dynamics of the local outbreak, and whether it is conjoined with other public health measures. The case is strongest when a low- or zero-incidence state bans entry from high-incidence ones; the case is weakest when a high-incidence state indiscriminately bans travel without simultaneously implementing other public health measures to stem local transmission.


What of condition (3)? Here, the crucial issue concerns the comparative effectiveness of bans versus other kinds of entry restrictions, such as masking, mandatory testing, vaccination, and/or quarantine. Here, the evidence is far less clear. There have been comparative studies of this issue. Most studies thus far, as a recent review, have focused on the early stages of the pandemic, rather than current post-peak stage. However, there’s some evidence suggesting that, in low or no COVID states, bans are much more effective than other entry restrictions and that single-interventions, such as testing only, fare worse than travel bans. Yet, it’s not clear how much this generalizes to states with higher baselines. There’s also evidence that multi-layered approaches, involving masking, quarantine, testing, vaccination, and reduction in overall travel volume can be quite effective in preventing the importation of cases to the local population.


More evidence needs to be gathered. My best guess is that whether travel bans have a comparative effectiveness advantage over multi-layered approaches will be largely determined by two factors. The first is overall travel volume. In a low-volume environment, the comparative difference between entry bans and multi-layered interventions will be minimal; in a high-volume environment, it might be more substantial. The second concerns the epidemiological situation in the destination and origin states. In low COVID states, bans will be much more effective, especially when implemented against high incidence states; in states with substantial outbreaks, they’ll make little difference. So, while I think some travel bans likely meet condition (3), many likely do not.


Before deciding whether such measures can be justified, we need to consider condition (4): the costs associated with such measures. There are, to begin, the costs to the residents of host states: being cut off from friends and family members, loss revenue from tourism, and the like. But I want to focus on the costs to outsiders. Here, two factors are key.


First, while entry bans impact all potential entrants, they do not impact all equally. Different international travelers have markedly different interests in international mobility. Simplifying somewhat, we should distinguish between tourists, immigrants, and refugees. It is comparatively easy to justify banning non-essential temporary entry than other forms of mobility. Tourists typically have no significant interest at stake in border crossing, although exemptions should be made for those who travel temporarily for important purposes, such as visiting family. It is harder to ban the entry of immigrants. Immigrants often have quite weighty reasons to move, such as to pursue opportunities denied to them in their state of origin or because of their deep, interpersonal relationships with those who live in those states. Exclusion sets back their interest to a much greater degree. This means that, except in rare circumstances, states should not ban entry of those on immigrant visas, nor stop issuing such visas for those who have legitimate claims to enter.


It is now reasonable to worry that what began as temporary measures may remain in place indefinitely, or, indeed, be weaponized as one more tool in states’ anti-immigrant toolkits.

Furthermore, the global community of states has an obligation to ensure that, even during a global pandemic, those in need of protection are provided it. As Patti Lenard has argued, even during a global pandemic, “the movement of the most vulnerable, who face imminent harm, must be permitted to continue.” So, refugees—roughly, those who have been forced to leave their country in order to escape war, persecution, or natural disaster—and asylum seekers—those seeking to apply for special protection in a specific state, should in general be exempted from such bans. Unfortunately, however, many states have used the pandemic as an excuse to pursue their anti-immigrant and anti-refugee agendas, as the Trump administration did, and the Biden administration continues to do, with Title 42. So, while entry bans for nonessential travel are often justified, justifying the use of such bans to exclude immigrants is much harder; excluding those in dire need of protection is almost always impermissible, especially in absence of arrangements to ensure that those excluded are given access to protection elsewhere. In these latter cases, the costs of the ban outweigh the harms it prevents.


The second decisive factor in assessing the costs of travel bans is temporal. It is one thing to ban entry temporarily from high-risk states during a crucial phase of the pandemic, as most states did in early 2020. A temporary ban excludes only temporarily, and so the setback to migrants’ interests is usually minor; extended exclusion is quite another matter. Many states’ entry bans have now been in place for over a year and a half. It is now reasonable to worry that what began as temporary measures may remain in place indefinitely, or, indeed, be weaponized as one more tool in states’ anti-immigrant toolkits.


There’s sometimes a good case to be made in favor of COVID-19 entry bans. However, the pandemic does not give states a blank check to indefinitely bar all forms of international mobility. Moreover, bans are at best a temporary solution: COVID-19 can’t be stopped by bans, except perhaps at the price of dystopian autarky; the only real solution is global cooperation, which includes ensuring everyone, the world over, can access vaccines. Rather than overlying on travel restrictions, states ought to cooperate to create the conditions under which they are no longer needed.


Disclaimer: Any views or opinions expressed on The Public Ethics Blog are solely those of the post author(s) and not The Stockholm Centre for the Ethics of War and Peace, Stockholm University, the Wallenberg Foundation, or the staff of those organisations.