3 ms·
Good post discussing Rt (rarely brought up), but a few points are lacking: * in the face of increasing (and volatile) testing capacity, Rt is being significant
by usaar333 7y ago
Good post discussing Rt (rarely brought up), but a few points are lacking:
* in the face of increasing (and volatile) testing capacity, Rt is being significantly over-estimated by looking at case counts. It's improbable CA still had an Rt above 1 the first week of April with covid deaths linear by the second week. More likely Rt was 1 about a week after the SIP (late march).
* Ignoring "herd immunity" effects of Rt. Some of the "under control" states (NY, Louisiana) have had very high infection rates which in their own end has dropped Rt down. NYC is a strong example of this - with > 20% of the city having been infected, well, Rt will drop dramatically just by so many contacts already having immunity.
* Implying this argues for states locking down now. I agree there is heavy evidence favoring lockdowns weeks ago to have avoided many deaths, but at this point, any lockdown is going to take a week to have an impact on even confirmed cases. The most susceptible populations (essential workers) are the very ones exempted from lockdowns (and less susceptible ones have already voluntarily socially distanced), so there's likely not much gain to be had. Sweden is conveniently our low density control group using mostly voluntary measures (WA State is similar through March 23) and its peak passing a week ago is a sign that Rt drops under 1 faster than you think.