- Population density
- % Black population (higher mortality)
- Average age
- Island (or nearly an island)
- Cultural norms of conformity
- Strong states vs. Federal govt.
- Vitamin D exposure
- When they got first infection
- How open the borders
- How seniors are cared for
- Sex rates and number of partners
- Fake news effect
- Privacy limits
- Data credibility
- Lying about contact tracing
- Which "type" of coronavirus dominated
- Comorbidities