Chop Suey

A bit of everything.

In my role as a Statistical Ambassador, I write about statistics.

This article collates short comments about various topics. This includes Germany’s reproduction number, YouGov surveys, representative samples, and more.

Germany’s Reproduction Number

On 22nd June, Sky News reported:

Coronavirus: Germany’s R number rockets again — from 1.79 to 2.88

Germany has a low number of infected people. The estimated reproduction number is sensitive to localised outbreaks. It reflects what has happened 8 to 13 days ago. The Sky News article does not express that the number is an estimate, nor any uncertainty. Also, it is a dimensionless number, and not a “rate”.

This is from the Robert Koch Institute report (which the Sky News article does not link to):

This value reacts sensitively to short-term changes in case numbers, such as those caused by individual outbreaks. This can lead to relatively large fluctuations, especially if the total number of new cases is small. The current estimate of the 4-day R-value is 2.88 (95%-prediction interval: 2.16–3.73) and is based on electronically notified cases as of 21/06/2020, 12:00 AM.

Estimates of the reproduction numbers (R-value and 7-day R value) were between 2 and 3 during the last few days. This is mainly related to local outbreaks which are described above, the outbreak in North Rhine-Westphalia playing a…