UC Berkeley
https://news.berkeley.edu/2020/04/24/study-challenges-reports-of-low-fatality-rate-for-covid-19/
"A comparison of daily deaths in Italy since January 2020 with those over the previous five years there indicates that the fatality rate in that country for those infected with the new coronavirus is at least 0.8%, far higher than that of the seasonal flu and higher than some recent estimates.
Extrapolating from the Italian data, University of California, Berkeley, and Lawrence Berkeley National Laboratory data scientists estimate that the fatality rate in New York City and Santa Clara County in California can be no less than 0.5%, or one of every 200 people infected.
These conclusions contrast with those of a study posted online last week by Stanford University epidemiologists, who pegged the fatality rate at between 0.1% and 0.2%. An affiliated team from the University of Southern California (USC) this week reported a similar fatality rate in Los Angeles.
The difference, the researchers say, is likely due to many deaths among older people that have not been counted in the official Italian statistics. The team found a much higher fatality rate for those over 70 years of age: In Lombardy, a region hit hard by the pandemic, those between 70 and 79 had a 2.3% infection fatality rate, while those 80 to 89 had an almost 6% fatality rate. Nearly 13% of those over 90 died.
The team also estimated, based on the predicted fatality rate for those infected with the new coronavirus and the positivity rate for those tested for COVID-19 in New York City, that about one-quarter of that city’s population has been infected with the virus. This agrees with the recent announcement by New York Gov. Andrew Cuomo of 21% infection.
The team’s predicted infection rate for Santa Clara is around 1%, while that for Los Angeles is around 2%, based on current mortality rates.
Given known infection and fatality rates on the Diamond Princess cruise ship, the team also calculated an upper limit on the fatality rate for those infected: about twice the lower limit, or 1%, for New York City and Santa Clara County.
With essentially everyone in Bergamo infected, and the known deaths since January — predicted to be more than 6,000 out of a population of 1 million — it was easy to calculate the lowest possible infected fatality rate: 0.56%.
For Lombardy, the researchers estimated that the lowest possible fatality rate was even higher: about 0.84%. They also estimated that 23% of the population of Lombardy was infected, as of April 18 — on average, 35 times the number of positive tests in the province."