How speedy lockdowns save lives

AS SUMMER ARRIVED, Europeans and Americans might have hoped for a covid-free spell, with the deadly peaks of spring a distant memory. That now looks unlikely. New infection hotspots have emerged in Britain’s Midlands, Germany’s west and throughout America. Even as the virus is rampaging through developing countries, people in the West are worried about a second wave.

It is too soon to predict how severe such outbreaks will be. Yet data from the first wave show how important it is for governments to respond quickly. Most East Asian countries with existing contact-tracing systems and experience of viral outbreaks contained covid-19 almost immediately. Western governments resorted to blanket lockdowns, which have crippling economic side-effects. Those that did so fastest contained the disease most effectively.

Europe shows this pattern clearly. Take Italy: the Lombardy region was hit sooner and harder than anywhere else on the continent, and issued a stay-at-home order relatively early, on February 22nd. As a result, Italy’s south was largely spared. The same pattern holds for France, which contained the virus mostly to Paris and the east. Germany, Austria and Switzerland all imposed national or regional lockdowns before they had recorded 60 deaths. By contrast, Britain already had 300 deaths by March 23rd, when its government ordered people to stay at home. This slow response allowed the virus to reach the entire country: 90% of Britons live in a region that has at least 25 confirmed deaths per 100,000 residents. That, in turn, has made it harder to reopen the country for business. Sweden, which did not impose a lockdown at all, has suffered a similarly widespread epidemic.

America’s experience with covid-19 has been more complicated. Its first wave, which primarily hit New York and New Jersey, looks like that of Italy or France. Stay-at-home orders, which most states had issued by early April, came too late to prevent lots of deaths in north-eastern cities but soon enough to protect the rest of the country. However, whereas most European countries closed their borders to each other, only half of American states imposed restrictions on interstate travel. But many governors, wary of political risks, chose to relax lockdowns even as confirmed cases reach new heights. Arizona, Florida and Texas did so quickly, and are now trying to close shops and restaurants again.

Researchers at Imperial College London estimate that Europe’s policies prevented 3m deaths by May 4th. And subnational data collected by The Economist suggest this was partly because stay-at-home orders contained the virus geographically. In an analysis covering 200 administrative units, such as American states and Italian regions, we found that stay-at-home orders substantially reduced the probability of the virus spreading to new areas. Imposing such a restriction on a region with fewer than 100 cases knocks 50% off its chance of reaching 25 deaths per 100,000 people in the next fortnight. Lockdowns are blunt tools, but they do save lives. ■

Sources: Johns Hopkins University; WHO; EU; University of Oxford; Flaxman et al. (2020); national statistical and health agencies

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