Covid-19 August 2, 2021

We look at the COVID-19 confirmed cases for US counties compared to various demographics, vaccinations and Presidential election results.

Vaccinations

Vaccination data per county are from: https://data.cdc.gov/Vaccinations/COVID-19-Vaccinations-in-the-United-States-County/8xkx-amqh/data

Confirmed cases per county data are from: https://usafacts.org/visualizations/coronavirus-covid-19-spread-map/. Note that Hawaii, Texas and Alaska data is missing.

Presidential election results are from: https://raw.githubusercontent.com/tonmcg/US_County_Level_Election_Results_08-20/master/2020_US_County_Level_Presidential_Results.csv

Fig 1	Fig 2

In Fig 1 it is seen that counties that voted for Biden have a higher vaccination rate. The average full vaccinations for Beiden are 44% +- 16% versus 36% +- 13% for Trump.

The trendline in Fig 2 shows a negative slope indicating the more the county leans to Trump the less likely people are to be vaccinated.

Looking in more detail at the Trump and Biden election return distributions we see below:

Fig 3

Fig 4 from

https://brilliantmaps.com/2020-county-election-map/

Fig 5

It is seen in Fig 3 that there are over four times more counties won by Trump compared to counties won by Biden. This can also be observed in Fig 4 by looking at a map of results by county from https://brilliantmaps.com/2020-county-election-map/. However, as one includes the county populations in Fig 5 by means of a bubble plot one can see the impact leans more to Biden.

Frequency histograms of % of the population fully vaccinated for counties won by Biden and % of the population fully vaccinated for counties won by Trump are shown in Fig 6.

Comparing the y scales it is again apparent that many more counties lean to Trump.
The peak for Biden is between 51% and 56% vaccinated whereas for Trump it is between 31% and 36%.
As measured by the full width at half max the Biden peak is much wider (Biden 31-36% - 66-71%, Trump 26-31% - 41-46%).
There are a surprisingly large number of counties with % fully vaccinated below 16% (Biden ~40, Trump ~140)
- This corresponds to ~ 2.4 million people from Biden counties and 4.1 million from Trump counties.
- For Biden the bulk of these counties are in Virginia (71%), followed by Georgia (25%) and Massachusetts (5%)
- For Trump the bulk of the counties are in Georgia (55%), Virginia (39%), and West Virginia (19%), followed by Colorado (2.5%), Nevada (2.5%), North Dakota (2.5%), Arizona (0.6%) and Louisianal (0.6%).
- For Biden these counties contain ~2.4 million people, for Trump they contain ~ 11.7 million people

Fig 6

Various Demographics

Here we look at the correlations between various demographics etc.

Presidential election 2020

Another way of observing how Biden was more popular in the more densely populated counties is seen in Fig 7 where we plot the point difference against the population density and see that the Pearson R² correlation (a measure of the total variation of y explained by the predictor (regressor) x) is ~28%, and the Pearson r (the correlation between x and y) = sqrt(R²) ~ 53%.

Fig 7

US COVID-19 Cumulative cases from 1/1/2021 thru vs demographics

Below we see the US by county COVID-19 cumulative cases from 1/1/2021 thru 7/29/2021 cases plotted against 8 demographics. It is seen that there is very little correlation against any of the demographics. The table below summarizes the R², r and a and b in the trendline y = a.x + b

Metric	R squared	r	a.x	b
per capita income	0.0074	0.086	-2E-05x	4.45
% white non hispanic	0.0112	0.106	0.008x	4.5
% unemployed	0.0067	0.082	0.086x	3.57
% poverty	0.0095	0.097	0.26x	3.54
% finish college	0.0049	0.070	-0.65x	5.9
% black	0.0099	0.099	0.0104x	3.82
% unemployed	0.0067	0.082	0.086x	3.57
population per sq mile	0.0042	0.065	6E-05x	3.9

Conlusions

For the US counties there is very little correlation between COVID-19 confirmed cases and many demographic metrics.
The number of counties that voted for Trump exceeds the number who voted for Biden by over a factor of 4.
However the Biden counties contain more people.
In terms of number of counties vs full vaccination, the peak for Biden is between 51% and 56% culy vaccinated whereas for Trump it is between 31% and 36%.
As measured by the full width at half max the Biden peak is much wider (Biden 31-36% - 66-71%, Trump 26-31% - 41-46%).
There are a surprisingly large number of counties with % fully vaccinated below 16% (Biden ~40, Trump ~140)
- This corresponds to ~ 2.4 million people from Biden counties and 4.1 million from Trump counties.
- For Biden the bulk of these counties are in Virginia (71%), followed by Georgia (25%) and Massachusetts (5%)
- For Trump the bulk of the counties are in Georgia (55%), Virginia (39%), and West Virginia (19%), followed by Colorado (2.5%), Nevada (2.5%), North Dakota (2.5%), Arizona (0.6%) and Louisianal (0.6%).
- For Biden these counties contain ~2.4 million people, for Trump they contain ~ 11.7 million people
- A few counties have < 1% of their population fully vaccinated.