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T HE SPREAD of covid-19 is most often measured by two numbers: how many people are infected, and how many have died. The first is very uncertain. Some carriers show no symptoms, and most countries do not test people who seem healthy. Because data on infections are unreliable, researchers have focused on deaths. Yet new statistics suggest that current fatality numbers may also understate the damage.

Official death tolls for covid-19 may exclude people who died before they could be tested. They also ignore people who succumbed to other causes, perhaps because hospitals had no room to treat them. The latter group has been large in other disasters. For example, when Hurricane Maria struck Puerto Rico in 2017, America recorded only 64 deaths. A study later found that the surge in total deaths was close to 3,000. Many occurred in hospitals that lost power.

Such analysis is not yet possible for nations battling covid-19. The only European country whose total death rate (as calculated by Euro MOMO , a research group) had spiked by March 20th was Italy. This estimate is based on a group of cities. Unfortunately, Italy does not break down covid-19 deaths by city, precluding a comparison of covid-19 and total deaths in the same area.

However, journalists and scholars have crunched their own numbers. L’Eco di Bergamo, a newspaper, has obtained data from 82 localities in Italy’s Bergamo province. In March these places had 2,420 more deaths than in March 2019. Just 1,140, less than half of the increase, were attributed to covid-19. “The data is the tip of the iceberg,” Giorgio Gori, the mayor of Bergamo’s capital, told L’Eco. “Too many victims are not included in the reports because they die at home.”

Comparable figures can be found across Europe. In Spain El País, a newspaper, has published the results of a study by the government’s health research centre, showing that “excess” deaths in the Castile-La Mancha region were double the number attributed to covid-19. Jean-Marc Manach, a French reporter, has found a similar disparity in the department of Haut-Rhin.

These differences may shrink over time. Official counts of covid-19 fatalities could be updated to include people who have already died, because confirming the cause sometimes takes several days. The toll from other types of death might fall soon: lockdowns could reduce accidents and violence, and many frail covid-19 victims were already likely to die of other causes. And mortality data are noisy in smaller regions—especially hard-hit ones that may not be representative of entire countries.

Still, the official covid-19 count will always seem too low in places like Nembro, a Bergamasque town of 11,000 people. It suffered 152 deaths in March, with only 39 attributed to the virus so far. “Almost all the old people got it,” says Luca Foresti, a researcher. “And therefore they died, a lot.” ■

Sources: Claudio Cancelli; Luca Foresti; L'Eco di Bergamo; El País; INSEE; Santé Publique France; Ministero della Salute; Tuttitalia; Ministerio de Sanidad; Datadista; Instituto de Salud Carlos III; Instituto Nacional de Estadística; InTwig

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