(Neil’s Note: This was a blog comment I made in response to Christopher Monckton’s article “Are Lockdowns Working?” at https://wattsupwiththat.com/2020/04/04/are-lockdowns-working/#comment-2956309, about the efficacy of lockdowns at lowering the rate of spread of the currently raging coronavirus epidemic. I made some further comments in replies, too).
The former mathematician in me decided it was about time to use the data we have to make a direct assessment of Christopher Monckton’s hypothesis that the lockdowns are working.
What I did was look, not at comparisons between countries, but at the graphs of total cases and daily new cases which are readily available on worldometers.info. As long as the reporting of cases within a country is done in the same way each day, I should be able to make reasonably reliable comparisons between the numbers of cases in a country at different stages of the epidemic. I simply picked the top 12 European countries in terms of total number of cases, and looked at the graphs for each.
First up was Spain. Something interesting jumped right out of the paper at me when I looked at the total cases graph. The curve comes in two parts; an exponential part, followed by a pretty much linear part. The transition in Spain was quite sharp, around March 24th. The daily new cases graph shows it, too; new cases were increasing exponentially up to about that date, and since then have been increasing far less, or even static. The Spaniards seem to have brought in their lockdown very quickly on March 13th and 14th, so the change in the regime came about 10 days after lockdown. Not at all far from the incubation period of the virus, of which the best estimate I have heard is 6 to 14 days.