The Stupid-Simple Model still appears to be beating the IMHE

As of April 17, the Institute for Health Metrics and Evaluation is predicting  60,308 US COVID-19 deaths by August 4, 2020.[1]  (Down from their  prediction of 68,841 yesterday, and from a prediction 61,545 for that date made on April 12.)

Essentially, this is a contest between the Stupid-Simple  Model (SSM) and the IHME. 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. And it’s still predicting that. That’s 4 days from now! Who will turn out to be closer to correct? 


Below is the recent growth in fatality rates:


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: 1.18
2020-04-08: 1.16
2020-04-09: 1.12
2020-04-10: 1.13
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

For the SSM, I  average the last 8 days’ exponential growth and get 1.1059. We then take yesterday’s numbers:

2020-04-17: Deaths: 3,857; Accumulated deaths: 36,773

Finally, we project forward using the SSM, seeing that the SSM anticipates more fatalities  by 4 days from now (Apr 22) than the IHME predicts for Aug 4. 

2020-04-18: Increase: 4,265 Total: 41,038
2020-04-19: Increase: 4,717 Total: 45,755
2020-04-20: Increase: 5,217 Total: 50,972
2020-04-21: Increase: 5,769 Total: 56,742
2020-04-22: Increase: 6,380 Total: 63,123
2020-04-23: Increase: 7,056 Total: 70,179
2020-04-24: Increase: 7,804 Total: 77,984
2020-04-25: Increase: 8,630 Total: 86,614
2020-04-26: Increase: 9,544 Total: 96,159
2020-04-27: Increase: 10,555 Total: 106,715
2020-04-28: Increase: 11,674 Total: 118,389
2020-04-29: Increase: 12,910 Total: 131,300
2020-04-30: Increase: 14,278 Total: 145,578
2020-05-01: Increase: 15,790 Total: 161,368

[1] https://covid19.healthdata.org/united-states-of-america