Rationale

• By late summer and fall 2020, U.S. K–12 school reopening decisions were highly decentralized and varied significantly by state, district, and even individual schools.
• The CDC noted that decisions about whether and how to reopen were largely made at the local level, resulting in a broad range of approaches: fully in‑person, fully remote, and various hybrid models with differing safety protocols.
• Reporting in major U.S. media at the time documented that:
  • Some districts (often in parts of the South and Midwest) reopened with mostly in‑person instruction and relatively limited mitigation measures.
  • Many large urban districts (e.g., Los Angeles, Chicago, parts of the San Francisco Bay Area) remained fully remote into fall 2020.
  • Others (e.g., New York City) used hybrid or phased reopening with strict precautions such as masks, cohorting, reduced class sizes, and staggered schedules.
• This produced exactly the “mixed bag” / heterogeneous national picture described in the normalized prediction, rather than any uniform national policy.

Given contemporaneous documentation of widely divergent local policies and mitigation levels in fall 2020, the prediction that U.S. school reopenings would be heterogeneous by locality is substantially accurate.