For each of the fifty states and the District of Columbia, the IRS Statistics of Income (SOI) provide data on the number of tax returns filed in that state, the number of tax exemptions taken on those returns, and the amount of adjusted gross income declared on those returns.
The SOI provide data on the outflow of tax filers from each state to all other states and on the inflow of tax filers to each state from all other states. The number of tax returns was relabeled “households,” as the number of tax returns moving between states very closely approximates the number of moving households. Note that for tax purposes, two spouses in a married couple who file separately are considered distinct households.
The net values in these visuals were calculated by subtracting each outflow measure from each inflow measure for each state pair for each year.
For example: the net migration of taxable income between California and all other states for 2014-15 was calculated by subtracting California’s outflow of adjusted gross income to all other states from California’s inflow of adjusted gross income from all other states. The resulting negative value indicates that more money flowed from California to all other states than vice-versa in the 2014-15 tax year.
California Inflow from other states: $1,166,914,145,000 in Adjustable Gross Income
California Outflow to other states: $1,168,927,588,000 in Adjustable Gross Income
California Net Migration to other states = Inflow – Outflow = $1,166,914,145,000 - $1,168,927,588,000 = -$2,013,443,000
A tax return is a document that each taxpayer files with the IRS. Each tax return contains information – such as the taxpayer’s income – used to calculate the taxpayer’s tax liability.
A tax exemption is an allowance that reduces a taxpayer’s taxable income, functioning similar to a deduction.
Each taxpayer’s adjusted gross income is their gross income minus specific adjustments such as their personal exemptions and itemized deductions.
Foreigners are individuals filing returns where the state is in the United States in one year and foreign (APO/FPO, Puerto Rico, U.S. Virgin Islands, overseas, or other) in another year.