Is COVID-19 Primarily a Disease of Wealthy Countries?
or are wealthy countries giving poorer countries their diseases?
GDP and COVID-19: a Possible Correlation
First posted April 7, 2020
Rewritten June 19, 2020
I wrote this article in early April after observing that countries that were hit hardest by the COVID-19 pandemic tended to be predominately wealthy countries. One usually expects epidemics to hit poor countries much harder than wealthy countries; but COVID-19 appeared to be an exception.
On April 7 and April 28 the correlation between GDP (by rank) and number of confirmed COVID-19 cases (also by rank) was either moderate (0.3≤ρ<0.5) or high (ρ≥0.5) depending on how the countries were chosen. (see table below)
Since then, I've run correlations on March 21, May 17, June 1 and June 16.
The correlation in March was not so strong as in April. Also the correlation fell off in May, but still remained moderate. By June, some of the correlations fell below the moderate range. The main reason appears to be that some wealthy countries: notably New Zealand, Australia, and many East Asian countries such as China and South Korea brought their epidemics under control and were surpassed in number of COVID cases by less wealthy countries. Indeed, in May, the correlation held at April levels when New Zealand, Australia and all of East Asia were removed. By mid-June, even this correlation began to wane. (see table below)
To a lesser degree, the pandemic raging out of control in some relatively poor countries: most notably Afghanistan, brought the correlation down from its April levels. Those familiar with Jared Diamond's “Guns, Germs and Steel” will recall that spreading disease has typically been one of the most effective ways in which wealthy countries have subdued poorer countries.
Also of note is that countries that were hit early by the epidemic and brought it under control early, now have far fewer cases overall than many countries in which the epidemic hit later. At this time, the United States, which peaked in April, ranks number 1. The United States never brought its epidemic under control and appears to be headed for a second peak. The epidemic came late to the next three countries, in order: Brazil, Russia and India, where the epidemic has either peaked recently or is yet to peak.
Recent research shows that the COVID-19 virus is mutating and appears to be becoming more contagious and virulent. This could at least partially account for why later outbreaks appear worse than earlier ones.
It would seem to make more sense to use GDP per person and COVID cases per million people, rather than to correlate by rank. I tried this; but the results were not encouraging. There was no correlation to be found.
Since the countries that have a large population tend to also have a high GDP, I tried correlating population with number of COVID-19 cases. The correlation gradually increased from -0.02 in March to 0.32 in mid-June. This makes sense, as all other factors being equal, infections should eventually become proportional to population.
Here are some likely causes for the observed correlation between GDP and confirmed COVID-19 cases: I think the first two are probably the most important from the standpoint of this article.
I intend to run these correlations again on July 1 and perhaps on various other dates.
1. People in wealthy countries tend to be more mobile and therefore better able to spread the virus.
2. Many people in wealthy countries tend to be lacking in social discipline and feel a sense of entitlement. E.g.: “Screw this social distancing crap, I gotta go do my thing.”
3. More testing is carried out in wealthy countries.
4. Many people in poorer countries have enough problems staying alive and healthy already without worrying about a new virus with at most a 5% mortality rate.
5. Poor countries may be less likely to report confirmed cases than wealthier countries.
In the April article, two other possible causes were also mentioned:
In view of the May and June data, both seem highly unlikely.
6. Genetics: Most (but not all) of the countries with a large number of cases per population size tended to be European or have large populations of European ancestry.
7. Perhaps this is simply random noise.
The data for the graphs and table below come from these two pages at worldometers.info:
The table below gives the number of confirmed COVID-19 cases by country and the rank of each country at 0:00 hrs gmt for the dates March 21, April 7, April 28, May 17, June 1 and June 16. The table also gives various correlations between GDP and COVID-19 cases by rank and a correlation between population and COVID-19 cases. Only countries that are in the top 50 by GDP or in the top 50 by rank in COVID-19 confirmed cases on at least one of the specified dates appear in the table.
COVID-19 cases by country
GDP (2017) by country
A scatter plot for each specified date is also included below.