While 21.2% of New York City residents tested positive, only 3.6% of residents from upstate New York have the antibodies.
The case rate in upstate NY (everything outside of NYC) is about 1.1%, so this would suggest about 2/3 of the infections are asymptomatic (actually a little more, because some in the sample would be recently positive for the virus, but not yet have developed Abs). This is very much consistent with many other studies, mostly of the virus rather than of antbodies, that have been discussed here, which suggest 50-75%.
But also note that the 3.6% figure should be an absolute maximum that the false positive rate could be--even if there were no true positives at all, which obviously wouldn't be the case--so unless the NYC tests were done differently in some way, it would seem that false positives would not have a major effect on the estimate of what proportion of people have Abs in the city. And the case rate for the city is not that much higher than upstate, about 1.6%.
A statistician argues that lockdowns don’t work.
https://www.thepublicdiscourse.com/2020/04/62572/
He defines lockdowns very precisely, as including three types of policies: compelling people to stay at home except for essential purposes; bans of gatherings of small numbers of people; and closing businesses indiscriminately. He isn’t opposed to many restrictive policies, including quarantining sick or exposed people; closing schools; travel restrictions; and outlawing large assemblies. He believes all of these practices clearly reduce spread of the virus.
Some of his main evidence that lockdowns don’t work comes from examining their effect on deaths. He begins by citing studies indicating that on average, most people die from C19 at least twenty or more days after infection. He then looks at the pattern of deaths following lockdowns in several major countries, and concludes that in most cases the number of new deaths peaked and began to fall before this twenty day period. IOW, he believes other, less restrictive measures, that were put in place before the lockdown, must have been the cause of the fall in number of deaths. He then goes on to provide evidence that these other measures work, even estimating their effectiveness (using county data from all over the U.S.) with a statistical model that determines how many days the measure has to be in practice to save one death per 100,000 people.
A well-thought out analysis. However, I think the conclusion lockdowns don’t work is overdoing it. He might argue at best that they don’t add any additional benefit, but to say that stay at home orders, for example, don’t reduce the spread of the virus, and therefore deaths, doesn’t make sense. How could they not?
In fact, his examples, though showing that peaks in deaths begin before this twenty day period ends, don't follow them long enough to see whether they continue to drop. Perhaps a further effect, due to the lockdowns, would be evident.
Also, I don’t know how one interprets the U.S.—granted, a very heterogenous situation—where the number of deaths has been more or less constant for the past two weeks. (By the way, what happened to that projection of 60,000 deaths in the U.S., I think by early August? We're at about 50,000 now, and appear likely to reach 60,000 by the end of the month).
There’s also the example of Michigan, where a stay-at-home order began March 24. The number of new deaths seemed to peak around April 16, 23 days after the order, suggesting that the order did indeed work by the author’s criterion. But after three days of lower numbers, a new high was reached on April 21, and the succeeding two days saw death totals around what had occurred during the peak. There are other factors, of course, that can affect the number of deaths and the author does take into account some of them in his county-by-county model.
By the way--this supports a point Cannavaro was making earlier--some people are touting some of these Ab tests as proof that the mortality rate is very low, only around 0.1%, no worse than the flu. Don't look now, but Belgium is already more than halfway there, with deaths per million of population at 0.056%. So unless half the population or so of Belgium is already infected, the mortality rate for that country almost certainly is greater than 0.1%.
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