[A note on these predictions: the following is a coldly analytical look at fatalities counts. Every single death is an enormous personal tragedy to the families, friends, and associates of the person who died, and such an analysis seems to completely ignores that fact. And yet, only by such pure analysis can we gain the tools needed to successfully fight the virus and reduce, and finally end, the tragedies. And that should be our goal. Accordingly, here we take a bit of time to take a hard look at the numbers.]
As of April 24, the Institute for Health Metrics and Evaluation is predicting 67,641 US COVID-19 deaths by August 4, 2020.[1] Their prediction for August 4 has been varying quite a bit; the prediction for that date made on April 12 was 61,545, and it was 60,308 on April 19. It does seem that their predictions are rising, bringing them a bit more in line with my Stupid Simple Model (SSM).
Essentially, this is a contest between the SSM and the IHME’s predictions that were made on April 12. On April 12, the IHME predicted 61,545 deaths by Aug 4. And on that same day, the SSM predicted more fatalities than that by April 22. It’s now past April 22, so the SSM was wrong. However, it still appears that it may turn out to be _much_more correct than the IHME.
Essentially, this is a contest between the SSM and the IHME’s predictions that were made on April 12. On April 12, the IHME predicted 61,545 deaths by Aug 4. And on that same day, the SSM predicted more fatalities than that by April 22. It’s now past April 22, so the SSM was wrong. However, it still appears that it may turn out to be _much_more correct than the IHME.
See [2] for a description of the theoretical basis of the SSM.
While the contest is to see whose predictions for August 4 that were made on April 12 were more correct, both models are still being updated. Today, the SSM is predicting almost exactly 61,545 deaths (specifically, 61,493) on April 26, just 2 days from now.
Below is the recent growth in fatality rates. It depicts the multiplicative factor by which one day’s count of fatalities was more than the day before's:
2020-04-01: 1.24
2020-04-02: 1.26
2020-04-03: 1.18
2020-04-04: 1.13
2020-04-05: 1.13
2020-04-06: 1.14
2020-04-07: 1.19
2020-04-08: 1.15
2020-04-09: 1.13
2020-04-10: 1.12
2020-04-11: 1.1
2020-04-12: 1.08
2020-04-13: 1.07
2020-04-14: 1.1
2020-04-15: 1.1
2020-04-16: 1.16
2020-04-17: 1.12
2020-04-18: 1.05
2020-04-19: 1.05
2020-04-20: 1.04
2020-04-21: 1.06
2020-04-22: 1.05
2020-04-23: 1.07
While the contest is to see whose predictions for August 4 that were made on April 12 were more correct, both models are still being updated. Today, the SSM is predicting almost exactly 61,545 deaths (specifically, 61,493) on April 26, just 2 days from now.
Below is the recent growth in fatality rates. It depicts the multiplicative factor by which one day’s count of fatalities was more than the day before's:
2020-04-01: 1.24
2020-04-02: 1.26
2020-04-03: 1.18
2020-04-04: 1.13
2020-04-05: 1.13
2020-04-06: 1.14
2020-04-07: 1.19
2020-04-08: 1.15
2020-04-09: 1.13
2020-04-10: 1.12
2020-04-11: 1.1
2020-04-12: 1.08
2020-04-13: 1.07
2020-04-14: 1.1
2020-04-15: 1.1
2020-04-16: 1.16
2020-04-17: 1.12
2020-04-18: 1.05
2020-04-19: 1.05
2020-04-20: 1.04
2020-04-21: 1.06
2020-04-22: 1.05
2020-04-23: 1.07
For the SSM, we average the last 8 days’ exponential growth and get 1.0742. We then take yesterday’s numbers:
2020-04-23: Deaths: 3,329; Accumulated deaths: 49,951
Finally, we project forward using that rate of exponential growth applied daily:
2020-04-24: Increase: 3,575 Total: 53,526
2020-04-25: Increase: 3,841 Total: 57,368
2020-04-26: Increase: 4,125 Total: 61,493
2020-04-27: Increase: 4,431 Total: 65,925
2020-04-28: Increase: 4,760 Total: 70,686
2020-04-29: Increase: 5,113 Total: 75,800
2020-04-30: Increase: 5,493 Total: 81,293
2020-05-01: Increase: 5,900 Total: 87,193
2020-05-02: Increase: 6,338 Total: 93,531
2020-05-03: Increase: 6,808 Total: 100,340
2020-05-04: Increase: 7,313 Total: 107,653
2020-05-05: Increase: 7,855 Total: 115,508
2020-05-06: Increase: 8,438 Total: 123,946
2020-05-07: Increase: 9,063 Total: 133,010[1] https://covid19.healthdata.org/united-states-of-america
[2] The idea behind the SSM is that models like that IHME are too attached to details of the current situation that are very likely not reflective of the long-term situation. Since we don’t know the truth of what is going to happen tomorrow, we don’t really know whether the day-to-day multiplicative increase in fatalities is going to be greater or smaller than it is now. Since we don’t now which way it will go, we consider it to be safest to assume it will remain the same. We are therefore considering no data whatsoever beyond the daily published fatality counts. They may go down as social distancing has more of an effect, or they may go up because deaths that were classified as due to other illnesses get reclassified as due to COVID-19, or because there is a big protest in Kentucky where many people become infected. We just don’t know what will happen. So, according to the SSM, the most reasonable estimate is that growth will be similar to what we’ve been recently experiencing, since that estimate is in the center of the range of possibilities.
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