King County didn’t just lose residents. It lost billions of dollars in income. Newly analyzed IRS migration data shows more than 68,000 tax filers left King County in 2023, taking approximately $2.19 billion in adjusted gross income (AGI) with them, according to reporting by the Puget Sound Business Journal. The findings raise new questions about the long-term health of the region’s tax base as Seattle-area leaders continue expanding public spending while businesses, jobs, and higher-income residents increasingly look elsewhere. According to the Business Journal’s review of IRS county-to-county migration records, nearly one-third of departing King County tax filers relocated to...