Open letter to the PM

Dear Boris Johnson,

I am by no means your greatest fan, but I thought you ought to know that the R0 number is now (3rd November 2020) below 1. That is to say, your 3-tier system has, to some extent, worked. Though it may well be best to stick with the 4 week lockdown-2, already announced. We still have much to learn about hygiene.

In the attached picture I have plotted the logarithms (base 10) of the daily new cases as reported on https://coronavirus.data.gov.uk. The horizontal axis shows the days of the year (day 279 is 5 Oct,, day 294 is 20 Oct., day 308 is 3 Nov.). 

It is clear that the rising line in blue (data from the first 3 weeks of October) cannot be extended through the most recent data (20 Oct - 3 Nov), shown in red.

The rising blue data show a doubling time of 24 days. The least-squares line of best fit is objective, but is not a close fit because of chance vagaries of the data (R-squared=0.62). The falling red data show a halving time of 200 days. (The line is again the least-squares line of best fit). That is to say, in late May 2021 we would still have 10,000 new cases a day (and c. 70 deaths a day) unless we improve our personal hygiene, (or we have a vaccine).  

So the 4 weeks of lockdown-2 should help. In June and July we had 40 times less virus buzzing around, but most people were foolishly unaware that the R0 number was already above 1. (See: https://occidentis.blogspot.com/2020/09/covid-19-case-data-uk.html ). Personal hygiene deteriorated further in early September. 

Yours sincerely, Ian West

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Ian West
9 Thenford Road, Middleton Cheney,
BANBURY, OX17 2NB,
Tel: 01295 713 889; (Mobile: 07474 572 588)

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