A Brief Statistical and Geostatistical Survey of the Relationship between COVID-19 and By-Mail Balloting in the 2020 North Carolina General Election

Adding to the already polarizing 2020 general election was the COVID-19 pandemic. One way in which this pandemic
greatly affected the election was through an increased participation in by-mail, or mail-in, ballots. The state of North
Carolina experienced a 316 percent increase in by-mail votes between 2016 and 2020, when approximately 977,186 votes
were cast by mail. It is no surprise that this increase was due to the COVID-19 pandemic; however, these by-mail voting
patterns are spatial in nature and vary across the state. This research measures to what degree COVID-19 rates affected
by-mail voting rates. Using geographic information systems data developed from robust tabular files provided by the
North Carolina State Board of Elections, by-mail votes were calculated and mapped at ZIP code scale and compared to
COVID-19 rates measured at different dates. By-mail rates taken from final absentee tallies for the highest and lowest
COVID-19 ZIP codes saw no significant differences across multiple dates (30 September 2020 and 31 October 2020)
when COVID-19 data were collected. COVID-19 hot spots (high COVID-19 rates surrounded by other high COVID-19
rates) were extracted using geostatistical techniques and compared to COVID-19 cold spots (low COVID-19 rates surrounded
by other low COVID-19 rates). It was found the lowest by-mail rates actually occurred in these COVID-19 hot
spots across both dates, as well a metric that expressed percentage change in COVID-19 rates in the month before the
2020 election.