Many wonder about the accuracy of the Coronavirus data. We look at the number of deaths and find that a quadratic fits very well. Is this coincidence? Is it too good to be true?
Coronavirus data can be found here:
We plot the number of deaths below using the number of days since 22 January 2020:
We develop a quadratic which fits the data:
The equation for the curve is D = 2.78d^2+28 where D is an estimate of the number of deaths and d is the number of days since 22 January 2020.
The factor 2.78 was calculated by by minimising the the sum of the squares of the differences (4960.418 leaving out 17 February, it is however plotted).
The average difference (Diff) between the actual data and the formula calculations was -0.14 suggesting that this is a useful formula.
We use the formula to estimate deaths in the next 400 days:
The number of deaths appears very low in comparison with other simulations.
We leave you to draw your own conclusions.
We note that, as of the last few days (later after 12 February when the method of diagnosing cases changed from lab tests to xrays, resulting in a spike of over 1400 new cases on that day), the cumulative total number of cases is an average of about 40 times the cumulative total number of deaths each day, down from about 45 times for earlier in February. We use the factor F=40 to estimate the total number of cases (C) i.e. C = 40D and
D = 2.78d^2+28 where D is an estimate of the number of deaths and d is the number of days since 22 January 2020.
The factor F=40 indicates a death rate over 1/40 = 2.5%
(some cases may die at a later date).
We may look further into the factor F in another post when we have more data for d>21 (i.e after 12 Feb). F=40.4 generates only three less cases than reported for 16 Feb (d=25).
We anticipate a vaccine will be available next year, so we may only need to consider up to 400 days (about 18 million people infected, less than 450,000 deaths).
Here is the previous version of the same graph:
Once again the official figures and hence these estimates appear very low. Most simulations calculate millions of deaths (e.g. 65 million) for a similar outbreak.
I leave you to form your own opinion.
I hope the Chinese data is not fake news.
I also hope we do not get infected.
Note: After writing this post I discovered this page:
Lancet nCov2019 propagation model PDF Download (free):
Lancet nCov2019 Model