US counties — commuter flows dominate

County-level GTP drill (3,258 counties; commuter-flow tells the story).

Strawman. Phase 1 ships a county-list with balance-sheet drill-down; Phase 2 builds the county choropleth as a real interactive map.

US counties

3,258 counties. Same balance-sheet identity. At this scale, the cross-border story is commuter flows — income earned in one county, spent in another. The economic reality most Americans actually live.

Why counties matter

A bedroom suburb and its downtown neighbor look almost identical on a GDP map — production is captured where the work happens. But on a wealth map they diverge sharply: Manhattan accumulates produced assets and financial wealth; Bergen County accumulates household wealth (housing, education, retirement claims) that the Manhattan-earned income built.

You cannot see this dynamic at the country scale. You cannot see it at the state scale. You can only see it when the unit of measurement is small enough to be on one side or the other of a commuter flow.

What’s here at launch

• County list with balance-sheet drill-down per county (3,258 entries)
• The “GTP” (Gross Territorial Product, HQ-bias corrected) is the income base, not GDP — corrects the systematic distortion that GDP introduces at sub-national scales
• The commuter-flow story foregrounded as the defining relationship at county scale

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