Do International Travel Restrictions Halt the Spread of Pandemics?

How fast did the COVID-19 pandemic spread around the world? What with planes, trains, and automobiles now commonplace, you’d think it would be pretty quick compared to past pandemics. But Michael Clemens and Thomas Ginn decided to check this out, and they found little difference over the centuries:

The 1918 influenza epidemic spread faster than the 2019 coronavirus epidemic. The 1889 and 1957 influenza epidemics were a little slower, but not by much:

If spread depends heavily on the modern ‘age of mobility’, the spread of recent pandemics should be supercharged relative to older pandemics with similarly infectious pathogens. But there’s nothing like that in the data. Across the four past pandemics we study, from 1889 to 2009, the time it took for the pathogen to reach the median person on earth only varied by *six weeks*.

….We separately show, for each of the four past pandemics, that the time-of-arrival has no negative relationship with mortality. Staving it off a bit longer did not save lives. Action behind the border did; inaction did not.

This doesn’t actually surprise me that much. Mobility may have been lower in the past, but it doesn’t take a lot of people to spread a pathogen. One or two will do quite nicely. To spread from, say, Europe to the US in 1889, you just have to wait for that one person to sail across the Atlantic. This adds a week or two compared to traveling via United Airlines, and then another week or two because the probability of that one guy sailing over is lower than it is today. But once he’s here, it’s all over.

The authors stress that emergency restrictions on international travel during a pandemic aren’t completely useless. It’s just that their effect is small: halving a country’s exposure to international mobility produces a delay in pandemic arrival on the order of only one week. Most of the benefit of social distancing (and travel restrictions are just a form of social distancing) comes from reducing personal interactions inside national borders.

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. It's our first time asking for an outpouring of support since screams of FAKE NEWS and so much of what Trump stood for made everything we do so visceral. Like most newsrooms, we face incredibly hard budget realities, and it's unnerving needing to raise big money when traffic is down.

So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate