Published behavioral erosion estimates

What this dataset measures

We included every top-rate or millionaire tax we could find, from 2004 on, for which both a pre-collection official estimate and a later collection figure (or official re-estimate) are published in a source we could open. Taxes with no published bracket-level collections (New Jersey 2018 and 2020, New York 2021) and New Jersey's 2004 tax (whose estimate we could not retrieve from a source) are excluded. Where one tax has several years, we include each year that has a matching estimate. The Massachusetts row includes both the Department of Revenue's forecast and the Tufts dynamic estimate, because the second is the only pre-enactment estimate in the set that cut revenue for behavioral responses.

Geography

California, Massachusetts, New York, Maryland, Oregon, Washington

Unit of observation

One estimate-vs-actual comparison for one tax and one revenue period

Update cadence

Ad hoc; updated when new collection figures are published

Curator

FactHub Research Team

Supporting files

Source snapshots, manifests, quality reports, documentation, and other materials used to produce or review this release.

• results.json Derived table · application/json · 15.4 KB (15,799 bytes)

  Saved-analysis results written by build_fva.js: ratio rows, verified-only rows, counts, per-tax summary and erosion rows.

• build_fva.js Transformation manifest · text/javascript · 13.9 KB (14,195 bytes)

  Node.js script holding every typed input value and computing the tables and results (node build_fva.js).

Saved analyses

Sources

1. California Legislative Analyst's Office Year-by-year Proposition 30 revenue estimates (table 'Proposition 30 Revenue Estimates')

   Retrieved October 21, 2026. California state government publication. Facts and figures quoted; document linked, not hosted

   Reliability: Government. Nonpartisan fiscal adviser to the California Legislature; prepares the official ballot-pamphlet fiscal estimates. The handout reproduces the ballot-analysis estimates by year.

2. California Legislative Analyst's Office Estimated Proposition 30 revenue generated, FY2011-12 to FY2013-14

   Retrieved October 21, 2026. California state government publication. Facts and figures quoted; page linked

   Reliability: Government. LAO's November 2014 estimate of what Proposition 30 raised; LAO says the amounts remain subject to change.

3. California Legislative Analyst's Office 2016-17 budget assumption for Proposition 30 income-tax revenue

   Retrieved October 21, 2026. California state government publication. Facts and figures quoted; document linked

   Reliability: Government. Official ballot analysis of Proposition 55 (2016). The $7 billion figure is the state budget's assumption, not a final tabulation.

4. California Legislative Analyst's Office Pre-enactment Proposition 63 revenue estimate

   Retrieved October 21, 2026. California state government publication. Facts and figures quoted; page linked

   Reliability: Government. Official ballot-pamphlet fiscal analysis for the November 2004 election.

5. California Mental Health Services Oversight and Accountability Commission Mental Health Services Act revenue by fiscal year Free copy

   Retrieved October 21, 2026. California state government publication. Facts and figures quoted; document linked

   Reliability: Government. State commission overseeing Proposition 63 spending; figures drawn from Governor's Budget fund condition statements, cash basis. The live site blocks automated access, so we read the archived copy.

6. Massachusetts Taxpayers Foundation FY2024 surtax projections presented at the consensus revenue hearing (DOR range $1,445M-$1,766M) and the $1 billion budget cap

   Retrieved October 21, 2026. Publication of a private nonprofit. Facts and figures quoted; document linked

   Reliability: Advocacy group. Business-backed fiscal research group; it opposed the surtax campaign but here reports the official hearing projections in a table. The bulletin is dated January 30, 2023.

7. Massachusetts Department of Revenue Preliminary certified FY2024 surtax revenue ($2.199 billion)

   Retrieved October 21, 2026. Massachusetts state government publication. Facts and figures quoted; page linked

   Reliability: Government. Official DOR press release of August 9, 2024, reporting the July 24, 2024 preliminary certification; later certifications may revise it.

8. Tufts University Center for State Policy Analysis Static ($2.1B) and dynamic ($1.3B) estimates of 2023 surtax revenue

   Retrieved October 21, 2026. University publication. Facts and figures quoted; document linked

   Reliability: Academic. Nonpartisan university policy center, January 2022. Its dynamic estimate cut revenue about 35% for avoidance (central income elasticity of 1) and migration.

9. New York State Division of the Budget Original ($4.0B) and revised ($3.6B) forecast of the 2009 high-income surcharge

   Retrieved October 21, 2026. New York state government publication. Facts and figures quoted; page linked

   Reliability: Government. Governor's budget office press release of October 30, 2009 on the mid-year financial plan update.

10. Maryland Department of Legislative Services Pre-enactment estimate for the 6.25% bracket ($102.1M TY2008, $109.3M TY2009)

    Retrieved October 21, 2026. Maryland state government publication. Facts and figures quoted; document linked

    Reliability: Government. Nonpartisan legislative fiscal note on SB 46 (2008), revised April 4, 2008.

11. Maryland Department of Legislative Services Comptroller's figures for revenue raised by the 6.25% rate, TY2008-10

    Retrieved October 21, 2026. Maryland state government publication. Facts and figures quoted; document linked

    Reliability: Government. 2012 fiscal note quoting the Comptroller's Office on what the expired bracket raised.

12. Oregon Legislative Revenue Office Pre-vote revenue estimate for Measure 66 (Table 2: $504M from rates and phase-out; $472M net)

    Retrieved October 21, 2026. Oregon state government publication. Facts and figures quoted; document linked

    Reliability: Government. Nonpartisan legislative revenue office research report RR 6-09, November 19, 2009.

13. Oregon Business Report of the December 2010 LRO revised projection (about two-thirds of $504M) and first-year preliminary collections ($130M vs $180M)

    Retrieved October 21, 2026. News article (archived copy). Facts quoted; archived page linked

    Reliability: News report. Business magazine item of December 16, 2010, summarizing a Statesman Journal report on an LRO presentation; the LRO document itself was not found. The original page is offline, so we link the Internet Archive copy.

14. Multnomah County FY2022 Preschool for All forecast ($112M) and collections ($187M)

    Retrieved October 21, 2026. County government publication. Facts and figures quoted; page linked

    Reliability: Government. County news release of February 14, 2023. The county administers the tax with the City of Portland.

15. Willamette Week FY2025 Preschool for All forecast ($163M) and collections ($224M)

    Retrieved October 21, 2026. News article. Facts quoted; page linked

    Reliability: News report. Portland weekly reporting figures from the county's annual financial report, November 21, 2025; we did not read the county report itself.

16. Metro (Portland regional government) FY2024-25 original budget ($374.5M), Fall 2024 forecast ($323.1M) and actual collections ($325.0M)

    Retrieved October 21, 2026. Regional government publication. Facts and figures quoted; document linked

    Reliability: Government. Metro administers and spends the tax; this is its own year-end revenue report.

17. Washington Office of Financial Management (DOR fiscal note) Capital gains tax revenue estimate as passed (gross tax lines: $527M FY2023; $1,162M 2023-25)

    Retrieved October 21, 2026. Washington state government publication. Facts and figures quoted; document linked

    Reliability: Government. Multi-agency fiscal note for SSB 5096 (2021), revised June 22, 2021. Gross tax = Education Legacy Trust plus Common School Construction lines; the note's $442M state total also nets out a B&O tax credit.

18. Washington Department of Revenue Capital gains tax net payments by tax year, as of June 9, 2026

    Retrieved October 21, 2026. Washington state government publication. Facts and figures quoted; page linked

    Reliability: Government. DOR administers the tax; net payments are payments minus refunds as of the stated date and may change.

19. Washington Office of Financial Management (DOR fiscal note) Revenue estimate for the 2.9% capital gains surcharge ($151M FY2026)

    Retrieved October 21, 2026. Washington state government publication. Facts and figures quoted; document linked

    Reliability: Government. Fiscal note for ESSB 5813 (2025), dated May 5, 2025; assumes about 900 taxpayers and ERFC growth, with no behavioral adjustment stated.

20. Washington Research Council ERFC estimate that the 2.9% rate accounts for $331.9M of FY2026 capital gains revenue

    Retrieved October 21, 2026. Publication of a private nonprofit. Facts quoted; page linked

    Reliability: Advocacy group. Business-supported fiscal research nonprofit that generally opposes new taxes; here it reports a figure attributed to the state's Economic and Revenue Forecast Council.

21. Joshua Rauh and Ryan Shyu, American Economic Journal: Economic Policy 16(1), 2024 Behavioral erosion of California Proposition 30 windfall revenue (45.2% year 1, 60.9% within two years) Free copy

    Retrieved October 21, 2026. Working paper; abstract quoted. Facts quoted; paper linked

    Reliability: Peer-reviewed study. Peer-reviewed study using California tax-return data; Rauh is a Hoover Institution fellow. Erosion is measured against the authors' no-response counterfactual.

22. Conway, Iselin and Rork, 'Mult-No-More?' (working paper, April 2026) Migration revenue loss from the Preschool for All tax (about 8.5% of static 2022 revenue)

    Retrieved October 21, 2026. Working paper hosted by OPB. Facts quoted; paper linked

    Reliability: Academic. Economists at UNH, the Yale Budget Lab and Reed College; not yet peer reviewed. The authors call their estimate likely an upper bound.

23. Cristobal Young and Charles Varner, National Tax Journal 64(2), 2011 New Jersey 2004 tax: static yield ($1.08B, 2006) and migration revenue loss ($16.4M/yr)

    Retrieved October 21, 2026. Journal article; copy posted by the Vermont Legislature. Facts quoted; copy linked

    Reliability: Peer-reviewed study. Peer-reviewed study of New Jersey tax-return data; measures migration only, not reported-income responses.

24. Washington Office of Financial Management (DOR fiscal note) Behavioral assumption in the ESSB 6346 income-tax revenue estimate

    Retrieved October 21, 2026. Washington state government publication. Facts quoted; document linked

    Reliability: Government. Multi-agency fiscal note for ESSB 6346 (2026) as passed; states that affected taxpayers do not reduce taxable income and applies a 4.71% AGI cut for reduced IRS enforcement.

Limitations and reproducibility

Reproducible from public sources: Every estimate and actual value was typed from the cited source; build_fva.js computes the ratios, counts and per-tax summaries and writes the CSV tables and results.json. Running node build_fva.js reproduces the published files byte for byte.

• Estimates and actuals are not always on the same basis. Several actuals are later official estimates rather than final tabulations (California FY2011-12 to FY2016-17, New York SFY2009-10, Oregon 2009-11), and California Proposition 63 actuals are cash-basis receipts.
• Ratios are nominal and compare one estimate with one outcome; they say nothing about why the outcome differed. In particular, a ratio above 1 does not show that taxpayers did not respond to the tax, and a ratio below 1 does not show that they did.
• Estimators differ (legislative analysts, revenue departments, a university center, local budget offices), and some estimates were made shortly before collections (Massachusetts FY2024, Multnomah, Metro) while others were made before enactment.
• The Oregon outcome is a revised projection reported second-hand by Oregon Business, and the Multnomah FY2025 figures come from Willamette Week; these rows are marked Unverified.
• The set is small (18 comparisons, 10 taxes) and not a random sample; its timing is dominated by the 2008-09 recession and the 2012-2025 market expansion.
• Some forecast dates are approximate (see each forecast's note).