A Rebuttal of Christopher Snowdon’s Claims about False Positive COVID-19 Test Results
by Nicholas Lewis Christopher Snowdon on Channel 4 News Christopher Snowdon makes some reasonable points in his January 16th article in Quillette “Rise of the Coronavirus Cranks”. However, he conflates cranks and rational sceptics, resulting in much of his critique being wide of the mark or plain wrong, and rational sceptics being unfairly tarred with the same brush as cranks. A response to Snowdon’s general argument has since been published elsewhere. However, it does not challenge the key quantitative criticism that Snowdon makes. Snowdon asserts that claims by Mike Yeadon are “demonstrably nonsensical”. Specifically, he attacks Yeadon’s claim in an article in Lockdown Sceptics in mid-September 2020, that the vast majority of Covid cases identified by Pillar 2 (testing in the community, England) since May 2020 had been false positives. Snowdon accepts the mathematics but challenges Yeadon’s assumptions regarding the true positive rate and the PCR test false positive rate, of 0.1% (the rate found by the Office of National Statistics) and 0.8% (the low end of a 0.8-4.0% false positive rate range stated in a report by Government scientists). Snowdon wrote that Yeadon “did not draw the obvious conclusion that if the false positive rate of the PCR test was 0.8 percent, the ONS should find positives at least 0.8 percent of the time”. Snowdon may think that is...
