arguablywrong has taken a look at the projections the Feds are using for planning. He has some criticism of some features of their model: unfortunately he is almost certainly correct.
First, they accept CCP data. I am not sure what actually happened in Wuhan, but I am sure that A. things were at least as bad as admitted and B. the CCP (eventually) reacted with overwhelming energy, in a way that seems to a fit a much bigger disaster than admitted.
AW thinks that deaths are significantly underestimated in several countries (certainly Italy, Spain, and France) and that IHME errs by not considering this. Correct.
IHME model assumes that state that do not yet have infection measures will do so with a week. That would be nice.
They assume that once controls are imposed, the epidemic will shrink just as fast as it previously grew. If the original R0 is 3, the post-control R0 must be 1/3rd. Uh, why?
“They assume that state-wide infection controls are equivalent in effect with the controls the CCP imposed in Wuhan.” AW calls this assumption crazy, but surely a stronger word is called for. In their first try, the CCP tried these measures, which are more intense than any yet in the US:
- Blocking outward transportation from Wuhan
- Closing public transit and vehicular traffic inside Wuhan
- Compulsory mask-wearing in public places
- Cancellation of public events
- Self-quarantine of confirmed or suspected cases
That dropped the R0 from around 3.5 to 1.25 – which wasn’t enough. They moved on to
- Full quarantine of confirmed or suspected cases (i.e., extraction to a separate quarantine site), including contacts of confirmed cases
- Temperature monitoring of all residents
- Universal and strict stay-at-home orders for all residents
All of these errors are in the same direction.