Anmerkungen:
Nach Informationen von SSRN wurde die ursprüngliche Fassung des Dokuments May 23, 2020 erstellt
Beschreibung:
This note discusses metrics that have been used frequently during the coronavirus pandemic: (i) the growth in the number of cases and deaths; (ii) the time they take to double; (iii) the re-infection ratio, generally known as the reproduction ratio R; and (iv) the excess mortality above the norm. The analysis here compares the UK with other countries in Europe, and is based on the daily counts disclosed by the relevant government agencies. Compound daily growth rates are extracted from weekly changes in order to smooth out short-term fluctuations; the visualisation of doubling is made clearer with a log base 2 plot; and comparability is improved by weighting for population, by standardising starting times, and by accounting for excess deaths with respect to the previous year. It is shown how growth curves behave as they converge to zero, the point at which there will have been no new cases for an entire week. It is also shown how the effects of the epidemic peaked when the doubling time lengthened to about two weeks, and the rate of growth in the total number of deaths fell to about 5% per day. A simple benchmark for R is constructed as the ratio of this week's new cases to last week's new cases, which reaches zero when the number of confirmed infections stabilises