I don’t have any axes to grind on coronavirus (except perhaps on masks), so some of my posts may seem to conflict. But they probably conflict less than you assume. Earlier I did a post questioning whether summer would make the problem go completely away, pointing to a rapid rise in coronavirus cases in many tropical countries. Today, I’ll present three pieces of evidence that warm weather will help at least somewhat:
1. Warm weather in the US seems to help. The three big warm states (CA, TX, FL) have (per capita) caseloads well below the national average. The same is true of Arizona, Hawaii and Puerto Rico. And this is mostly true even if you exclude New York from the sample, as it biases the national figures.
2. A few weeks ago, I noticed that Australia and Canada had tracked each other very closely for a considerable period of time. But in the past few weeks they’ve strongly diverged, to the benefit of Australia. Perhaps the first cases were mostly imported, and now that community transmission is the key factor we see Canada doing much more poorly. You might wonder why I don’t compare Canada to the US, but I actually regard Australia and Canada as the more similar countries.
3. The tropical countries continue to have strong growth in caseloads, but it doesn’t seem as explosive as the previous growth in Europe and the US, especially given their huge populations. Of course there may be a delayed reaction, or perhaps flawed data. But as of today they seem to be doing better than I would have expected. India and Luxembourg?!?!?
In an earlier post I suggested that this is becoming a white man’s disease. If anything, that tendency has since become even stronger. South and East Asia have most of the world’s population, but only about 80 of the roughly 6000 coronavirus deaths today will be in that huge region. Africa is also mostly unaffected. Of the 26 countries with the highest active caseload, 25 are mostly white or mixed white (i.e. Brazil.) South Korea is 20th, and falling.
But a few weeks from now I might have a completely different view.
China’s active caseload has been steadily falling for many weeks. But the internal composition is interesting. The active caseload in China’s big cities (and some border regions) has been rising fairly rapidly, but the effects are masked by an even more rapid decline in Hubei province. At some point something will have to give. Either travel restrictions will slow the number of imported cases, or the total caseload will again begin to rise.
PS. Don’t confuse official national policies with reality. Governments in Brazil and Sweden have not adopted strong social distancing policies. But Brazilian state governments have done so and in Sweden I’d guess that at the individual level people are doing much more social distancing that if the epidemic did not exist. Someone correct me if I’m wrong in that assumption.