I guess the UK line in the Johns Hopkins chart, reported earlier, might well turn down at some point soon, as some other countries’ lines have.
But if we continue at 3 days for doubling of cases, according to my spreadsheet experiment, we will see over 1m cases after 40 days. See:
and the example outputs attached for 3, 5 and 7 day doubling.
If we had experienced (through the social distancing and other precautionary measures) and continue to experience a doubling period of 5 days (not on the chart but a possible input to my spreadsheet), it would lead to 25,000 cases after 40 days.
If we had managed to experience 7 days for doubling of cases (as Japan and Singapore seem to have done), then we would have seen 5000 cases at 40 days (but that’s where we are already, so too late for that outcome).
So the outcomes are VERY sensitively dependent on the doubling period, which I’m sure in turn is VERY dependent on the average number of people each carrier infects.
I haven’t modelled that part yet, but, again, assumptions apart, the doubling period would be an outcome of that number, together with how long cases last (before death or recovery) and whether re-infection is possible, likely or frequent. It all gets a bit more difficult to be predictive, rather than mathematically expressing known data.
On a more positive note, there is a report today of the statistical work of Michael Levitt (a proper statistician!), who predicted on February 21st, with uncanny accuracy, the March 23rd situation in China (improvements compared with the then gloomy other forecasts). See the article attached.