Population density once again invoked. Data say 'No'.

On Twitter recently, I see with increasing frequency once again, Population Density (persons/ Km²) invoked as the cause of increased cases or increased deaths due to COVID-19 infecting a country. Or sometimes, a part of a country. 


That might take the form of "More cases and deaths in Flanders (or Brussels) due to an elevated Population density."


So let's see what we can find in Germany.

Why Germany? 

Well they seem to have a pretty good outcome at this time (May 27, 2020) from the infestation of that country by SARS-CoV-2. So with such clear and positive and complete data, it should be easy to identify that Population Density effect.


Here is a summary panel (click to enlarge)


16 Regions in Germany, All Data


16 regions in Germany :

      • accounting for 98.99% of the total population
      • 179 365 COVID-19 cases, a median of 5152.5 cases per region
      • an enviable death rate (CFR) of 4.333±0.9756%, median 4.62% and a variance of only 0.010%
      • 90.206±2.4966% of these cases have now Recovered.
      • leaving only 5.461±2.5950% Actively ill.
      • the mean population of these 16 regions is 5 185 340,13±4 938 927,85 and a median of 3 270 769, with a mean population density of 709.26±1 1 11.90 persons per km². Amedian of 213.05 persons per km² and a large variance of 1 318 732.73 persons per km². With such a large variation in the population density, if cases and/ or deaths from COVID-19 are impacted by population density, this is a good sample to study to find such effects if they exist.


Data by Region


Region in Germany, Cases and Deaths


We add the Population Density


Region in Germany, Cases and Deaths, Pep density - 27 May


How do these look, sorted?

by Population density, since that is the hypothesis ...



Sorted by Population Density - 16 German regions - May 27, 2020



by Cases of COVID-19


Sorted by Cases COVID-19 per million - 16 German regions - May 27, 2020


If you see a link between cases and deaths, that makes sense since in this sample, 4.33±0.98% perish.

But is the population density value tracking right along? i think not.



Sorted, by Deaths from COVID-19



Sorted by Deaths from  COVID-19 per million - 16 German regions - May 27, 2020

Cases fit right along, but not that Population density column.


And since we used the word "fit."

How strong a correlation is there between the Population density as determining factor, and the Cases found? Clearly, if people are milling about, one squeezed against another, there just must be more Cases found. Right?

It seems like such a charmingly logical idea...


Population Density and Cases per million in Germany - 27 May, 2020


Well not.

A linear correlation coefficient of R² = 0.0512 is pretty darn weak. 

Translation: Increased population density does NOT associate with increased COVID-19 case load.



How about for deaths?

If some of these regions do not have enough hospital resources to treat the very sick in a high population density region, there just have to be more deaths. No doubt about it.


Population Density and Deaths per million in Germany - 27 May, 2020


Well not


There is great doubt. In fact, an R² value of 0.000151 says: "Please just forget about that hypothesis. It doesn't even merit the name, hypothesis."

That movie image of people packed in like rats in a medieval city, and someone screaming "Bring out your dead!" as he passes. Well if it fit in the 14th century (and others) for bubonic plague, it does not fit for COVID-19. 


Et point à la ligne, c'est tout. C'est la fin. 

Here are the population density data for Belgium, but please, don't even get me started...


Belgium - Population density



Addendum June 16 ...


Certainly fits with Brussels having the highest density, doesn'(t it? 


Décès par région, sommaire - 16 juin






I'm sure that even these fairly strong data will not keep someone on Twitter from Tweeting today:


"Well yes. Of course. 

You see, that region of France has a #much greater population density." Or the equivalent.


Hopefully, we'll never hear representatives of the Belgian government, voicing this hypothesis to explain results to the Belgian people.




Pop density NONSENSE




Yesterday's results in Belgium, 26 May, 2020 >>>>



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