Other experts said that India’s refusal to cooperate with the W.H.O. analysis was rooted in the country’s history of ignoring how data can inform policymaking.
“It’s natural to miss some of the Covid deaths,” said Dr. Bhramar Mukherjee, a professor of biostatistics at the University of Michigan School of Public Health who has been working with the W.H.O. to review the data. But, she added, “Nobody’s been this resistant.”
The Ministry of Health in New Delhi did not respond to requests for comment. W.H.O. officials said that India’s 2020 death figures were released too late to be incorporated into their calculations but that they would “carefully review” the data.
Nations that report Covid deaths more accurately have also been at the center of disputes over the reliability of excess death estimates. In Germany, for example, the W.H.O. experts estimated that 195,000 more people than normal had died during the pandemic, a significantly higher toll than the 112,000 Covid deaths recorded there.
But Giacomo De Nicola, a statistician at Ludwig Maximilian University of Munich, who has studied excess deaths in Germany, said that the country’s rapidly aging population meant that the W.H.O. analysis might have underestimated the number of people who would have been expected to die in a normal year. That, in turn, could have produced overestimates of excess deaths.
He said that the W.H.O.-assembled experts had accounted for trends in mortality, but not directly for changes in the age structure of the population. While Germany experienced excess deaths, he said, the W.H.O. estimate for the country “seems very high.”
Overall, the W.H.O. calculations were more conservative than separate analyses released earlier by The Economist and the Institute for Health Metrics and Evaluation.
Some experts said that the W.H.O. analysis benefited from relying more heavily than other estimates on actual data, even where it was incomplete, as opposed to statistical modeling.
Oscar Lopez, Karan Deep Singh, Sofía Villamil, Christopher F. Schuetze, Ivan Nechepurenko, Richard C. Paddock, Muktita Suhartono, Mitra Taj, Julie Turkewitz, Merna Thomas and Salman Masood contributed reporting.