Migration wealth velocity

Definition

Migration wealth velocity captures whether a place is gaining or losing per-capita wealth through population movement. We divide the average adjusted gross income (AGI) of new arrivals by the average AGI of departures, both measured at the household level via tax returns filed against new addresses.

Source data

• IRS SOI Migration Data — County-to-county tax-return based migration with returns, exemptions, and AGI by direction (2012–2022)

Steps

1. Pull annual IRS migration data at the county level: returns_in, AGI_in, returns_out, AGI_out.
2. Compute average AGI per inmover and per outmover.
3. Take the ratio; values > 1.0 mean inmovers are wealthier than outmovers.
4. For ZCTAs we attribute the county value uniformly.
5. Buckets: strong outflow (<0.85), modest outflow (0.85–0.97), balanced (0.97–1.03), modest inflow (1.03–1.15), strong inflow (>1.15).

Known limitations

• IRS migration is based on filing addresses; non-filers (the very poor) are systematically underrepresented.
• AGI is a federal tax concept; it excludes some income types (e.g., most Social Security) that matter more in retirement-heavy migration.
• County-to-county data does not capture intra-county moves.
• IRS publishes data with a 2-year lag; the latest year typically reflects the second-prior tax year.
• We compute the ratio at the household level; per-exemption (per-person) ratios differ slightly.

Where this metric appears

Every place page, the Highest wealth-attracting list, and the Migration Wealth Velocity Index.

Related methodology

• Net migration rate
• AGI per exemption (per-person variant)

Cite this methodology

Commerce Institute. (2026). Migration wealth velocity — Methodology. Retrieved from https://commerceinstitute.org/methodology/migration-wealth-velocity/.