Massachusetts Fair Share: Three Years of Revenue Overperformance and No Measured Flight — the One US High-Earner Tax with a Multi-Year Record

Massachusetts Fair Share: Three Years of Revenue Overperformance and No Measured Flight — the One US High-Earner Tax with a Multi-Year Record

Massachusetts is the only US jurisdiction named in this brief that has actually been collecting a high-earner tax long enough to have a track record, and the record now spans three full fiscal years. The Fair Share Amendment (passed November 2022) adds a 4% surtax on the portion of annual income above $1 million — an income surtax, not a wealth tax — with the threshold indexed ($1,107,750 for tax year 2026, per the Massachusetts DOR). The empirical question the brief asks — can it be implemented, and what does it actually raise — now has real data.

The revenue record: 2–3x the ballot-time estimate, three years running

When the amendment was on the ballot in 2022, the state Executive Office of Administration and Finance projected $1.2 billion annually. Actuals, per the January 2026 consensus revenue forecast reported by Streetsblog Massachusetts:

"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."

The Department of Revenue certified $3.1 billion for the first 10 months of FY26 (July 2025–April 2026), up 20% from $2.5 billion at the same point in FY25 — a third consecutive record year, with May and June still to collect. Notably, the official FY27 consensus forecast is $2.7 billion — below the FY26 run-rate — which tells you state forecasters expect mean reversion rather than extrapolating the surge.

The migration record: IRS data show no flight response

MassBudget's March 19, 2026 analysis of newly available IRS migration data (moves for taxes filed 2022→2023):

"The outmigration rate was 0.97 percent for these households in filings in 2023 compared to 1.15 percent in 2022, demonstrating that the surtax is not having the impact some detractors of the Fair Share had predicted.¹"

MassBudget adds that roughly 9 of 10 households leaving Massachusetts reported incomes below $200,000 — i.e., the leavers are the least likely to owe the surtax — and that by end of January 2026, Fair Share collections were running ~$200 million ahead of the prior year. This is consistent with the academic literature cited by CBPP: "the rich in high-tax states do not move any more often than those in low-tax states," with a 1 percentage-point top-rate increase producing only a ~0.14% reduction in a state's millionaire population.

The advocacy coalition that ran the 2022 campaign draws the maximal conclusion — "The skeptics who said multi-millionaires would flee for other states rather than pay their fair share are being proved wrong; the ultra-rich are clearly staying in Massachusetts and paying more in taxes" (Raise Up Massachusetts) — and that framing should be discounted as advocacy, but the underlying DOR certifications and IRS data are official numbers.

What this does and doesn't prove (adjudication)

1. Revenue-positive: yes, unambiguously, on certified numbers — three straight years at 2–3x the ballot estimate. But the overperformance is partly market beta: the base is capital-gains realizations and bonus income concentrated in ~1% of filers, so collections track equity markets. The FY27 forecast sitting below the FY26 run-rate is the forecasters themselves pricing in volatility. The honest reading is that the tax raises far more than scored and is more volatile than a broad-based tax — both things at once.
2. The flight premise fails the test so far — the core behavioral assumption that drives down wealth-tax revenue scores (high earners relocate) shows no sign of operating in the IRS data through 2023 filings. Caveat: that dataset covers only the first, partial implementation year; 2024–25 filings (full implementation, strong markets) aren't in it yet.
3. Administrability does not transfer to a wealth tax. An income surtax piggybacks on existing withholding, third-party reporting, and annual returns — administratively trivial. Massachusetts proves the migration premise of wealth-tax scoring is weak; it does not prove that valuing untraded equity mark-to-market is feasible. That question remains with the international record (The Netherlands Retreats From Taxing Unrealized Gains: A Mark-to-Market Administrability Case Study, Europe's 2026 Reversal Wave: Sweden Debates Reinstalling What It Deleted, and the UK's Non-Dom Exodus Gets a Number).
4. Massachusetts is one leg of a three-state 2026 test alongside Washington's I-645 repeal vote (Washington I-645 Enters the Endgame: The Ballot-Language Effect, Two Debates, and the $3.1B–$3.5B Score) and California's Proposition 40 (California Proposition 40 Endgame: Newsom Backs the Ban, Hoover Scores a Net Loss, and the FTB War-Room Problem).