Crawford School of Public Policy

New research shows that closing borders in the first wave of the pandemic in 2020 reduced COVID-19 infections and fatalities and supported economic growth, Quentin Grafton, Dan Gordon, and Stein Ivar Steinshamn write.

Since the start of the COVID-19 pandemic there has been ongoing debate about the benefits of border controls in controlling the spread of the SARS-CoV-2 virus. Our recently published peer-reviewed paper in Economic Analysis and Policy used data on the growth in COVID-19 among similar Nordic countries – Denmark, Finland, Norway and Sweden – to evaluate the impact of international air border closures on COVID-19 cases, with some important results.

The World Health Organization (WHO) has been clear in its advice that countries should keep their borders open during the pandemic. It advised ”…against the application of travel or trade restrictions to countries experiencing COVID-19 outbreaks” and at the time said it “…does not recommend travellers as a priority group for testing.”

The WHO justified its advice on the grounds that ”…evidence shows that restricting the movement of people and goods during public health emergencies is ineffective in most situations and may divert resources from other interventions. Furthermore, restrictions may interrupt needed aid and technical support, may disrupt businesses, and may have negative social and economic effects on the affected countries.”

The WHO perspective was supported by some public health professionals including Anders Tegnell in April 2020, the Chief Epidemiologist at the Swedish Public Health Agency. He observed that “closing borders, in my opinion, is ridiculous, because COVID-19 is in every European country now. We have more concerns about movements inside Sweden.”

This ‘closed border’ argument recognises that, at any point in time, arrivals from different countries have a different probability of being infectious. Thus, if a country has, say, a COVID-19 infection rate of one per cent of the population, then we might expect, in the absence of any border controls, that one per cent of people arriving from that country are infected.

In the absence of effective quarantine on arrival, if daily arrivals are in the thousands or tens of thousands (and this is especially relevant when arrivals come to a country with a much lower infection rate) from countries where infection rates are one per cent of the population, there will likely be additional COVID-19 seeding events in the arriving country in the tens or hundreds per day.

Of course, where social distancing is widely practised, masks are used in public, testing is widespread, and contact tracing is highly effective, only a small proportion of these possible hundreds of seeding events from arrivals may result in a sustained COVID-19 outbreak.

But absent of these controls, including effective quarantine, or if these controls are implemented ineffectively, a highly susceptible population that has not yet been vaccinated against or infected with COVID-19 would likely suffer an epidemic from arrivals.

The first wave of COVID-19 infections in Europe, beginning first in Italy in February 2020, can be traced back to arrivals who had been in China, and their impact can be analysed empirically to see the effect on the growth of COVID-19 infections of different national border controls.

Using data on cases, fatalities, social distancing, and border controls, our research investigated the consequences of imposing full international air border closures on the weekly growth rate of COVID-19 infections in the countries studied, while controlling for different national levels of stringency in terms of social distancing and internal travel controls.

This investigation is a natural experiment because Denmark, Finland, and Norway imposed full border closure for most of April and May 2020 while Sweden did not. Analysis of the data showed that, on average, closed air borders resulted in a statistically significant negative effect on the growth in per capita COVID-19 cases for these countries.

These results indicate that Sweden suffered a 15 per cent growth in per capita cases of COVID-19 because it did not implement an international air border closure. In other words, Sweden’s decision not to impose an air border closure in the first wave of the pandemic in 2020, in part, explains its much poorer performance, relative to its Nordic neighbours, in per capita COVID-19 cases and fatalities.

The study also compared economic performance among Organisation for Economic Co-operation and Development (OECD) European countries, which includes the Nordic countries, and found that a poorer public health performance in terms of COVID-19 fatalities per capita in 2020 is associated with lower economic growth.

The WHO advice, at least from a public health perspective, was directly contrary to what our results show. In Nordic countries, imposing full international air border closures significantly reduced COVID-19 infections in the first wave of 2020.

At least in OECD Europe, there was also no discernible trade-off between the implementation of national measures that successfully controlled the COVID-19 fatalities per capita and overall economic growth in 2020. In fact, the opposite may be true – the countries that helped to keep their case numbers lower by closing international borders, appear to also have supported their economic growth during 2020. In sum, there can be both a public health and economic payoff from imposing effective international border restrictions during the pandemic.

With The New Normal: In Focus section, Policy Forum is rebooting our coronavirus pandemic coverage to address the changing situation. We hope you find the discussion valuable, and invite you to join in the conversation.