GDP: BEA nominal, 2020–2024. Population & change: Census PEP Vintage 2025. Avg wage: BLS QCEW county annual pay 2023 (CBP payroll÷employment fallback). Income per capita: BEA CAINC1 2024. Location quotient: employment concentration vs. the national base — CBP 2-digit, or BLS QCEW for deep sectors (2023). Unemployment: BLS LAUS, most recent month. Business formation growth: Census BFS county applications, 2020→2024 CAGR (2022+ counts carry Census differential-privacy noise). Affordability: BEA CAINC1 per-capita income CAGR minus FHFA county HPI CAGR, 2020→2024 — positive means incomes are outpacing home prices. Interstate & port distance: county centroid to nearest BTS National Highway System segment / USACE port or dock, computed by Economic Atlas. Suppressed cells show “—”, never zero.