SARS-Covid-2: A Crude Back-of-the-Envelope Estimation of Deaths

Disclaimer: I am not a medic, and not a pandemic modeling researcher. But I am a computer science researcher that has made models of various kinds since the 1990s, many published and sold, and I do have a background as a former Red Cross paramedic (yes, I know how to convert a hospital in case of an Ebola outbreak and such, and I have intubated/resuscitated folks).

This post is a response to various other models that I’ve seen and found too complicated. A complex model while we do not know much instils a lack of credibility in me.

Here is a very crude (back-of-the-envelope) calculation of the overall estimated deaths per country for two countries that I know a bit better and have been following online and offline since December.

The numbers are covering the full Corona pandemic period (not just up to a certain date). The forecast:

  • United Kingdom: between 66,500 and 798,000 deaths
  • Germany: between 8,000 and 96,000 deaths

This “model” is based on the following assumptions:

  • We don’t really know a lot, so we need wide confidence margins. Don’t believe anyone who gives you one number.
  • Because of our lack of knowledge about the disease, as tempting as it may be to run a simulation, I don’t feel comfortable with that approach, as it suggests “more science” than we have.
  • The % of population eventually infected is: 10%-60% (taken from expert statements)
  • The % of exitus letalis outcomes (% infected eventually dying from or in connection with SARS-Covid-2) is: 10%-20% (my own observation from JHU: 9%-22%, rounded to 10% best case and 20% worst case, thankfully at the time of writing we’re now down from 22% to 17%)
  • Country populations:
    Germany: 80 million
    UK: 66.5 million
  • Response effectiveness OoM: Germany: 10E-2; UK: 10E-1, the order of magnitude difference to a “do nothing” approach (which would treated as a 10E-0 multiplier) based on my observations.
  • Note there are absolutely no assumptions made about the actual duration by design – the above is a pure “part of the pie” computation.
  • Existing knowledge (model should be consistent with these):
    UK: at least 30k dead as of May 8
    Germany: at least 8k dead as of May 8

I will compare these numbers against body counts on 2021-05-05. If the model is good, the total numbers of deaths (hospital and otherwise) for the two countries will lie in the two interval brackets provided.

Potential future work includes:

  • apply to other countries;
  • refine the “response effectiveness multiplier” based on a set of critical policy elements being present or not in a country;
  • provide (separate) forecasts for the duration of the pandemic and the financial impact.

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