Official figures say there have been 55,000 covid deaths in South Africa since March 27th last year. That puts the country’s death rate at 92.7 per 100,000 people, the highest in sub-Saharan Africa. It is also a significant underestimate—as, it seems safe to infer, are all the other African data on the disease.
Over the year to May 8th the country recorded 158,499 excess deaths—that is, deaths above the number that would be expected on past trends, given demographic changes. Public-health officials feel confident that 85-95% of those deaths were caused by sars-cov-2, the covid-19 virus, almost three times the official number. The discrepancy is the result of the fact that, for a death to be registered as caused by covid-19, the deceased needs to have had a covid test and been recorded as having died from the disease. Although South Africa does a lot of testing compared with neighbouring countries, its overall rate is still low. And the cause of death is unevenly recorded for those who die at home.
South Africa is not particularly unusual in its levels of testing or in missing deaths outside the medical system. Excess mortality has outstripped deaths officially reported as due to covid-19, at least at some points in the course of the epidemic, in most if not all of the world. According to the most recent data, America’s excess deaths were 7.1% higher than its official covid-19 deaths between early March 2020 and mid-April 2021.
Studies of such mismatches have proved illuminating in some countries. For example, Britain saw excess deaths higher than official covid-19 deaths during its first wave, but lower than the official covid death rates in the second—an effect taken to show that measures to stop the spread of covid had saved lives which in another year would have been lost to other diseases, such as seasonal flu, perhaps. Something similar was seen in France.
But the excess-mortality method has failed to provide useful or robust global figures for the simple reason that most countries, and in particular most poor countries, do not provide excess-mortality statistics in a timely fashion. Global estimates have used the official numbers, despite knowing that the figure—currently 3.3m—surely falls well short of the true total.
To try to put numbers on how much of an underestimate it is—and thus on how great the true burden has been—The Economist has attempted to model the level of excess mortality over the course of the pandemic in countries that do not report it. This work gives a 95% probability that the death toll to date is between 7.1m and 12.7m, with a central estimate of 10.2m. The official numbers represent, at best, a bit less than half the true toll, and at worst only about a quarter of it.
As well as providing a new estimate of the overall size of the pandemic, the modelling sheds light on the distribution of its effects and on its overall course.
Unsurprisingly, most of the deaths caused by covid-19 but not attributed to it are found in low- and middle-income countries. Our figures give a death rate for the mostly rich countries which belong to the oecd of 1.17 times the official number. The estimated death rate for sub-Saharan Africa is 14 times the official number. And the first-and-second-wave structure seen in Europe and the United States is much less visible in the model’s figures for the world as a whole. Overall, the pandemic is increasingly concentrated in developing economies and continuing to grow.
To create these global estimates of total excess deaths during the pandemic, we drew on a wide range of data. Official counts of covid-19 deaths, however imperfect they may be, are available for most countries; they are shown in the top map on this page. So, frequently, are data on the number of covid cases and the share of covid tests that are positive. In general, if lots of tests are coming back positive, it is a fair bet that many more infections are being missed by a testing regime that is looking only at those seeking medical treatment and those near them.
In some places there have been seroprevalence surveys which show how many people have detectable sars-cov-2 antibodies, a sign of earlier infection. Other factors we thought might matter included the steps governments have taken to curb the spread of disease—such as closing schools—and the extent to which people moved around.
Demography matters a lot: more younger people typically means lower death rates. So, we inferred, do less obvious factors such as systems of government and the degree of media freedom. To take a specific example, excess deaths in Russia are 5.1 times greater than official covid deaths.
All told we collected data on 121 indicators for more than 200 countries and territories. We next trained a machine-learning model which used a process called gradient boosting to find relationships between these indicators and data on excess deaths in places where they were available. The finished model used those relationships to provide estimates of excess deaths in times and places for which there were no data available. A description of our methodology and the ways in which we tested it, as well as links to replication code and data, are here.
We estimate that, by May 10th, there was a 95% probability that the pandemic had brought about between 2.4m and 7.1m excess deaths in Asia (official covid-19 deaths: 0.6m), 1.5m-1.8m deaths in Latin America and the Caribbean (v 0.6m), 0-2.1m deaths in Africa (v 0.1m), 1.5m-1.6m deaths in Europe (v 1.0m) and 0.6m-0.7m deaths in America and Canada (v 0.6m). In Oceania, with only 1,218 official deaths, the model predicted somewhere between -12,000 and 13,000, the lower bound reflecting the possibility that precautions against covid-19 had reduced deaths from other causes.
There’s more at the link if you want to go deeper.
We will never know exactly how many people died from COVID during this pandemic. And it’s a long way from over. But they have developed good models to extrapolate death tolls like this and it’s already clear that the carnage is overwhelming.
This is why I find it so infuriating that Americans and Europeans are having to deal with fools who refuse to get vaccinated for political reasons when we are literally the luckiest people on the planet to have these scientific miracles at our disposal. How ungrateful we are.