COVID-19 April 21, 2020

Yesterday's numbers remain more or less in line with expectations.  As I mentioned yesterday, I will only update predictions roughly once per week because of the noise and oscillations in the daily data make it pointless to try and adjust the predictions more frequently.

Many states are starting to loosen restrictions to varying degrees.  It will be interesting to see how that affects the data going forward.  With a mean incubation period of about 5 days, delays in testing, and the lag between symptoms and hospital admissions, it may take a while before we know the impact.  Of course, just like the light from distant stars, the data we see on a given day is actually the reality as it was some time in the past.  I'm still not sure politicians and policymakers fully understand this.