TL;DR
The empirical ledger just got its first multi-year US dataset, and it complicates the exit narrative from last cycle: Massachusetts's Fair Share surtax has collected at 2–3x its ballot estimate for three straight years, with IRS migration data showing no flight response. Meanwhile Washington's repeal fight is now inseparable from a court election, and Hungary's revenue math is running an order of magnitude ahead of what anyone can actually see on paper.
Massachusetts: the first real implementation record, and it cuts against the flight premise
The migration critique that defined the California story just met its first controlled test with actual collections — and the tax outperformed.
"In fiscal year 2024, lawmakers budgeted for only $1 billion in Fair Share revenue, but actual tax collections were $2.2 billion. In fiscal year 2025, Fair Share tax collections surged to $3 billion." — Streetsblog Massachusetts
The migration data is the sharper finding: MassBudget's analysis of newly available IRS data shows the outmigration rate for high-income households fell after the surtax — 0.97% in 2023 filings versus 1.15% in 2022 — and roughly nine in ten households leaving Massachusetts reported incomes below $200,000, the least likely to owe the tax massachusetts-fair-share-implementation-record+1. This is the same behavioral assumption Washington's DOR concedes it cannot measure and that drove the California departures.
Two honest caveats keep this from being a clean win for the pro-tax side. The overperformance is partly market beta — the base is capital gains and bonuses concentrated in ~1% of filers, which is why the official FY27 forecast of $2.7B sits below the FY26 run-rate of $3.1B in ten months. And an income surtax piggybacks on withholding and third-party reporting; it proves the migration premise of wealth-tax scoring is weak, not that mark-to-market valuation of untraded equity is feasible massachusetts-fair-share-implementation-record+1.
What to watch: The 2024–25 IRS migration filings — the first data covering full implementation in strong markets — which will either confirm or break the no-flight finding.
Washington: the repeal vote and the court that would hear the challenge are on the same ballot
Washington's 9.9% millionaires' tax is fighting on three fronts, and the constitutional one may be decided by elections rather than argument.
"In August, the Department of Revenue estimated the tax passed this year would bring in $3.1 billion during the first fiscal year it takes effect and $8.3 billion between 2029 and 2031." — The Spokesman-Review
The new wrinkle this cycle: 5 of 9 Washington Supreme Court seats — including Chief Justice Debra Stephens — are on the same November 3 ballot as the I-645 repeal initiative, the first time in decades a majority of seats is up at once, and KOMO notes explicitly that these justices may decide statutes like the 9.9% tax washington-state-wealth-tax-study-and-constitutional-constraints+1. The Culliton v. Chase challenge filed by Rob McKenna's group turns on the 1933 uniformity doctrine — "income is property, and progressive income taxes are unconstitutional under existing law" — a question orthogonal to administrability.
The ballot-language fight is itself a scoring event: DHM polling found 57% would keep the tax when shown the Attorney General's fiscal statement, versus 44% opposition without it — a swing outside the 4.9% margin of error washington-state-wealth-tax-study-and-constitutional-constraints+1. Remember from last cycle: collections don't start until 2028/29, so the $3.1B score remains a projection with a two-year planning window for anyone inclined to relocate.
What to watch: The Nov 3 triple — repeal vote, court seats, and the fate of the Culliton docket — which will set the constitutional trajectory for years.
Hungary: the revenue claim meets visible arithmetic, and the gap is a full order of magnitude
Hungary's bill is still unpublished, but the first independent math on the party's revenue estimate is unkind.
"The four have a combined fortune of HUF3.78 trillion. A 1% annual levy on that combined amount would correspond to roughly HUF38bn in annual revenue, although the actual revenue from the proposed multi-rate system cannot yet be determined because the final rates, thresholds, exemptions and valuation rules have not been published." — bne IntelliNews
The party claims HUF 300–600bn annually; the visible top of the distribution — Mészáros, Csányi, Felcsuti, Veres — yields roughly HUF 38bn at 1%, so the entire claim rests on the unscored aggregate of fortunes between HUF 1bn and HUF 500bn plus compliance hungary-wealth-tax-proposal-2026-and-european-reversal-wave. The design detail that matters most for feasibility: the scope reaches foreign assets, and State Secretary Kovesdy himself names valuation of private companies and property as "one of the main challenges" — the same failure surface that broke the Netherlands' notional system and drove the repeal wave. An independent expert cited by RTL says verifying declarations "could take years."
What to watch: Finance Minister Kármán's bill, due within weeks or in the 2027 budget draft — the first official scoring of a reversal-wave wealth tax.
What surprised us
- The Massachusetts record is the strongest pro-administrability datapoint yet — and it doesn't even tax wealth. Three years at 2–3x the ballot estimate, with the flight premise failing in official IRS data, undermines the core behavioral discount in every wealth-tax score massachusetts-fair-share-implementation-record
+1. But the same finding warns against overreach: an income surtax says nothing about whether you can value untraded equity annually.
- Washington's constitutional fight may be won at the ballot box, not in court. Electing a majority of the supreme court concurrently with the repeal vote means the Culliton question could be settled by appointment-and-election dynamics before a brief is filed washington-state-wealth-tax-study-and-constitutional-constraints
+1.
- Hungary's own revenue number fails the sniff test before the bill even exists. A party estimate an order of magnitude above the visible arithmetic is exactly the kind of contestable assumption this brief exists to flag hungary-wealth-tax-proposal-2026-and-european-reversal-wave
.
Open threads worth a vote
- [watch] Washington Supreme Court elections: 5 of 9 seats on the Nov 3 ballot, including Chief Justice Stephens — the court that will hear the Culliton v. Chase challenge is being elected now. Vote on whether to track individual races. Threads