Cycle on Sep 14, 2026

I am going to check the open threads for the topic to identify active research questions, watches, and prior directions established by past cycles.

I will read the existing notes in the system for this topic to understand what has been documented so far and identify areas for refinement or expansion.

I will search for any updates or developments regarding: 1. California's 2026 Billionaire Tax Act (Initiative No. 25-0024 / Proposition 40 / Proposition 40 wealth tax etc.) 2. Washington State's Millionaires' Tax (Initiative 26-645, Initiative 645, or related constitutional litigation) 3. Norwegian wealth tax or Swiss capital flight (recent developments in 2026) 4. Spain's solidarity tax or wealth tax dynamics 5. Federal wealth tax discussions or updates. Let's start with a broad web search for recent news on California's wealth tax initiative (Initiative 25-0024, or Proposition 40) or Washington's Initiative 26-645 to see what the current status is as of mid-September 2026. This is particularly relevant as the elections are in November 2026, so campaign activity, polling, and legal challenges should be in full swing.

The search results give a goldmine of information! Let's examine what we have: 1. California Proposition 40 is indeed on the ballot for November 3, 2026. 2. It's officially called "California Proposition 40, One-Time Wealth Tax for State-Funded Healthcare, Education, and Food Assistance Programs Initiative (2026)" or "The 2026 Billionaire Tax Act". 3. It would impose a one-time 5% wealth tax on California residents whose net worth exceeds $1 billion (about 200–250 taxpayers), payable in annual installments of 1% over five years. 4. The tax applies to billionaires who were California residents as of January 1, 2026, to prevent immediate exit-based avoidance. 5. The Legislative Analyst's Office (LAO) analysis of Proposition 40 says: "Temporary state revenue increase from a new wealth tax on billionaires. These wealth tax revenues probably would add up to tens of billions of dollars spread over several years. Possible ongoing decrease of less than $1 billion per year in state income tax revenue collected from billionaires." 6. Let's look at the actual flight numbers: "Only 6 billionaires left California over its proposed wealth tax — but they took $27 billion in potential revenue with them" (Fortune, March 17, 2026) and "The tax escape map: Billionaires are bolting for Florida from the West Coast and taking some $29 billion in tax revenue with them... taxes owed by Page at about $14 billion and Brin at about $13 billion. Meanwhile 5% of Kalanick's and Thiel's wealth adds another $1.8 billion or so that brings the total potentially lost revenue to about $29 billion" (Fortune, August 30, 2026). 7. Let's look at the NBER Working Paper 35218 (May 2026) by Jasper Boll, Emmanuel Saez, and Gabriel Zucman: "California Billionaires: Wealth, Taxes, and Wealth Tax Revenue Estimates". Saez is one of the authors of Prop 40. 8. Let's search for this NBER working paper to get its precise details and figures. 9. Let's also check Washington State's Initiative 26-645 (or IP26-645) and the 9.9% progressive tax. Let's do a search for Washington's wealth tax / millionaires' tax updates. Let's search for the NBER paper first: "California Billionaires: Wealth, Taxes, and Wealth Tax Revenue Estimates" by Boll, Saez, and Zucman. This will give us the empirical core of the pro-side, while we can find the Hoover Institution's "The Net Present Value of the Billionaire Tax Act: An Assessment of the Fiscal Effects of California's Proposed Wealth Tax" (Rauh/Jaros) or other critiques for the con-side. Let's run a search.

Let's do a search on Washington State's wealth tax initiative, Initiative 26-645 (IP26-645), and the 9.9% tax. Let's see what the current state is. Is there an active campaign, polling, or legal challenges? Let's search.

Let's fetch the page `https://www.thestartuplawblog.com/initiative-645-tracker/` to understand the state of Initiative 645 in Washington. This is highly specific and gives a chronological tracker. Let's do a `web_fetch`.

The Startup Law Blog page is extremely comprehensive and details exactly where things stand in Washington State. Let's summarize: 1. In Washington, the 9.9% tax on income above the $1 million standard deduction (enacted via ESSB 6346 in 2026) remains law, effective January 1, 2028, unless voters repeal it or courts strike it down. 2. Initiative 645 (I-645) is certified for the November 3, 2026 ballot to repeal the 9.9% income tax. 3. There has been intense litigation over the "Public Investment Impact Disclosure" (PIID) required for the ballot. The disclosure will appear on the ballot as: "This measure would decrease funding for public K-12 education, higher education (including universities and community colleges), and human services (primarily healthcare)." 4. On September 3, 2026, the Washington Supreme Court split 4-4, denying Arthur West's motion to modify Commissioner Johnston's August 20 ruling that upheld the PIID. Thus, the ballot disclosure is fixed for November 3. 5. On August 12, 2026, the Department of Revenue quietly revised its estimates for the income tax: it now expects 25,000 households to pay the tax (up from 21,000), raising $3.1 billion in the first year (up from $2.7 billion), and $8.3 billion for the 2029-31 biennium (up from $6.9 billion). This is a substantial increase in projected revenue. 6. The constitutional challenge to the tax itself, *Petter v. State of Washington*, No. 26-2-00073-20, remains pending in Klickitat County Superior Court, backed by the Citizen Action Defense Fund. Rob McKenna and Phil Talmadge represent the plaintiffs. As of September 9, 2026, no dispositive motions are set and no injunction is in place. Let's check if there are other states or federal updates, or international updates. What about European wealth taxes? Is there any new development in Norway or Switzerland as of 2026? Let's search. Let's do a search for Norway wealth tax exit tax 2026. Or Swiss capital flight 2026. Or Spain wealth tax 2026. Let's run a search.

Let's fetch the Reuters article: `https://www.reuters.com/business/norways-wealth-tax-trades-millionaires-equality-2025-11-24/` to see the details on the Norwegian wealth tax, its exit tax, and the broader European context as of late 2025/2026. This is a very valuable and authoritative source. Let's do a `web_fetch`.

This Reuters article is incredible! It provides the perfect empirical detail on the Norwegian wealth tax, its trade-offs, and how it is functioning in late 2025/2026. Let's analyze: 1. Norway's wealth tax: Individuals pay 1% on net wealth between NOK 1.76M and NOK 20.7M, and 1.1% above that. In 2026, the PwC Worldwide Tax Summaries show the municipal rate is 0.35% and the state rate is 0.65% (total 1.0%), and above NOK 21.5M it's 0.75% state + 0.35% municipal (total 1.1%). The tax is broad: exactly 671,639 people (about 12% of the population) paid it in 2023. It generates about 0.6% of GDP. 2. The exit tax (utflyttingsskatt) is 37.8% (or 37.84% in 2026, which is the effective tax on share income / capital gains). It applies to unrealized capital gains above NOK 3 million when ceasing Norwegian tax residency. In 2024, loopholes allowing emigrants to defer payment indefinitely were closed (the old 5-year escape rule was eliminated; now the tax applies indefinitely). 3. The behavioral response / capital flight: - Data from conservative think-tank Civita shows 261 residents with assets above NOK 10 million left in 2022 and 254 in 2023 — more than double the typical rate before the hike. - Business magazine *Kapital*'s ranking of Norway's 400 richest people shows 105 now live abroad or have transferred wealth to relatives who do. - Despite this exodus, revenue from the wealth tax has climbed and now sits at 0.6% of GDP. - A paper by Princeton researcher Christine Blandhol estimates the latest tax changes will cut Norway's long-run output by 1.3% due to business owners departing (40% of emigrants are business owners). - On the other hand, research by Norway's statistics office (SSB) suggests that entrepreneurs have enough liquidity to pay, the burden falls overwhelmingly on the richest, and it does not straightforwardly hinder firm-level investment or employment. - The trade-off is summarized by NTNU Professor Roberto Iacono: "Not having a wealth tax leads to greater inequality, having one means less capital for startups. Politics needs to strike a balance." Let's do some more search on the Hoover Institution's paper or other con-side papers regarding California's Proposition 40 (the Billionaire Tax Act) to get their precise arguments and figures. We saw a reference to "Rauh et al. 2026" or "Walczak 2026" on the con-side. Let's search for "The Net Present Value of the Billionaire Tax Act" or "Ongoing State Tax Revenue Implications of the 2026 California Billionaire" to see their methodology and numbers. This will provide the balanced, adjudicated view the brief asks for.

Let's do a search on SSRN or Google for the text of "The Net Present Value of the Billionaire Tax Act: An Assessment of the Fiscal Effects of California's Proposed Wealth Tax" or just fetch the Hoover Institution summary page `https://www.hoover.org/research/net-present-value-billionaire-tax-act-assessment-fiscal-effects-californias-proposed` to see what their specific methodology and results are. Let's do a `web_fetch` on that Hoover page.

Excellent! Now we have the core arguments and numbers from both sides: 1. Proponents (Zucman, Saez, Boll - NBER Paper 35218): - Estimate that a 5% one-time wealth tax on California billionaires can raise about $100 billion. - Point out that California billionaires' wealth grew 144% from 2023 to 2025 (to $2.3 trillion by mid-2026), driven by the AI boom. - Note that billionaires pay only about 0.2% of their wealth in annual California income tax ($3.2 billion/year), and total California income tax paid is just 1.6% of their wealth gains over 2019-2025. - Argue that a permanent wealth tax on California billionaires would raise substantial additional revenue, even taking into account mobility responses. - They address the "flight" argument by showing that even if some leave, the revenue collected from the remaining ones remains massive, and that the con-side studies (like Hoover/Rauh) overestimate income tax losses by assuming the top billionaires (like Page, Brin, Zuckerberg) pay much more in California income tax than they actually do. (Since they have direct SEC data showing these top 4 pay only 0.04% of their wealth in annual California income tax, or $270M total per year, because they don't sell stock or receive dividends in many years). 2. Opponents (Rauh, Jaros, Kearney - Hoover Institution): - Point out that nearly 30% of the Billionaire Tax Act's tax base has already departed California (e.g., Sergey Brin, Larry Page, Peter Thiel, Travis Kalanick moving or changing residency). - Project that the tax will collect only about $40 billion over 5 years (not $100 billion) even in a "best-case scenario" that ignores lost income taxes. - Estimate that when accounting for the permanent loss of future state income taxes from these departing ultra-wealthy residents, the Net Present Value (NPV) of the tax is actually negative: -$24.7 billion. - Note that the measure amends the state constitution to lift California's cap on taxes on intangible personal property with no sunset, creating the constitutional infrastructure for a permanent wealth tax. Let's do a search on Spain's wealth tax / solidarity tax as of 2026. Is there any new development there? Let's search for Spanish wealth tax solidarity tax 2026. Or Spanish Constitutional Court rulings. This will help refine the Spanish wealth tax note `spanish-wealth-tax-regional-national-solidarity-tax-dynamic`. Let's run a search.

Excellent! Let's examine Spain's situation. 1. Spain's "Solidarity Tax on Large Fortunes" (Impuesto Temporal de Solidaridad de las Grandes Fortunas - ITSGF) was introduced in late 2022 (Law 38/2022) as a "temporary" tax for 2022 and 2023. However, it has been extended and effectively made permanent. 2. The tax serves as a "double-decker" backstop to the regional Wealth Tax (Impuesto sobre el Patrimonio). Under Spain's regionalized system, autonomous communities (like Madrid or Andalusia) had implemented 100% tax relief (bonification) to eliminate their regional wealth taxes to attract wealthy residents. 3. The federal Solidarity Tax applies to individuals with net assets exceeding €3 million (with a €700,000 personal exemption and a €300,000 habitual residence exemption, so it effectively applies above €3.7 million or €4 million). 4. The rates are progressive: 1.7% on wealth between €3M and €5.35M, 2.1% between €5.35M and €10.7M, and 3.5% on wealth above €10.7M. 5. To avoid double taxation, any regional wealth tax actually paid (Modelo 714) is fully deductible from the federal Solidarity Tax (Modelo 718). This means that in regions with an active wealth tax (like Catalonia), residents owe little or no Solidarity Tax because their regional tax covers it. In regions with 100% relief (like Madrid), residents now have to pay the federal Solidarity Tax, neutralizing the regional tax competition. 6. According to the Tax Foundation, the Solidarity Tax collected less than expected (around 40% of the €1.5 billion expected), as many taxpayers restructured their assets or used tax planning (such as the 60% rule cap, which limits the combined wealth and income tax liability to 60% of taxable income). Let's check if there are any federal wealth tax proposals or constitutional developments in the US (such as updates following the *Moore v. United States* Supreme Court case). Let's do a search on federal wealth tax proposals 2026 or Moore v United States wealth tax. Let's run a search.

Let's look at the March 26, 2026 press release on Representative Pramila Jayapal and Senator Elizabeth Warren reintroducing the *Ultra-Millionaire Tax Act*. Let's do a `web_fetch` on `https://jayapal.house.gov/2026/03/26/jayapal-warren-boyle-45-lawmakers-renew-push-for-wealth-tax-on-ultra-millionaires-and-billionaires/` to see the details of this legislative proposal, its estimated revenue, and its assumptions. This is a very recent federal update (March 2026). Let's fetch it.

This is a major federal update from March 2026! Let's analyze the *Ultra-Millionaire Tax Act*: 1. Reintroduced on March 26, 2026, by Representative Pramila Jayapal, Senator Elizabeth Warren, and Representative Brendan F. Boyle, with over 45 lawmakers. 2. It would apply a wealth tax to fortunes above $50 million: - 2% annual tax on the net worth of households and trusts valued between $50 million and $1 billion. - An additional 1% annual surtax (3% total annual tax) on net worth above $1 billion. (Wait, the text says: "an additional 1% annual surtax (3% total annual tax) on the net worth of households and trusts above $1 billion." Let's note that this is slightly different from the previous version which was 2% and 6% as a billionaire surtax, or maybe there are multiple versions. The press release says: "a 2% tax on wealth over $50 million—3% above $1 billion"). 3. Estimated revenue: $6.2 trillion over 10 years (according to a new analysis by Saez and Zucman, up from the previous score of around $3 trillion five years ago). 4. Target group: the wealthiest 260,000 households in America (or the top 0.15%). 5. Anti-evasion measures: $100 million in new funding for the IRS and a 40% "exit tax" on the wealth of ultra-millionaires and billionaires who renounce their citizenship to avoid the tax. Let's check if there are any other specific state proposals or issues. What about Massachusetts? The Massachusetts overperforming "Fair Share Surtax" (the 4% surtax on income over $1 million). Let's search for "Massachusetts Fair Share Surtax" 2026 revenue to see how it is performing and what the latest empirical figures are. This will help refine `state-level-wealth-tax-proposals-california-2026-initiative`. Let's run a search.

Let's fetch the Axios article or the MassBudget analysis of the FY 2026 General Appropriations Act to get the hard numbers on Massachusetts Fair Share surtax collections. Let's do a `web_fetch` on `https://mass.streetsblog.org/2026/01/14/fair-share-millionaire-tax-continues-to-exceed-expectations` to see the details of the surtax exceeding expectations. This is a very valuable empirical source on a high-income surtax (which functions similarly to wealth/millionaires taxes in state-level debates). Let's fetch it.

This is a fantastic empirical result! Let's analyze Massachusetts' Fair Share Amendment: 1. The Fair Share Amendment (approved by voters in November 2022, took effect in January 2023) imposes a 4% income tax surcharge on annual income over $1 million. 2. The revenues have consistently and significantly exceeded expectations: - In FY 2024, lawmakers conservatively budgeted for $1.0 billion in Fair Share revenue, but actual collections were $2.2 billion. - In FY 2025, Fair Share collections surged to $3.0 billion. - For FY 2026, the budget estimated $2.4 billion. - For FY 2027, the consensus revenue forecast announced in January 2026 expects $2.7 billion in Fair Share revenue (an 11% increase over the prior year's forecast of $2.4 billion). 3. These higher-than-expected revenues have allowed the state to fund public transportation (such as filling the MBTA's operating deficit) and education programs, and have flown into reserve funds. 4. This represents a strong, empirical case of a high-income surtax being highly revenue-positive and overperforming official projections, contradicting warnings of massive immediate capital flight or revenue collapse in Massachusetts. Let's do a quick search on public markets data to see if there is any macro backdrop or sector views we should pull. The system has `market_view` enabled, and we can check `kind=macro` to see if there is any interesting macroeconomic backdrop (like inflation, interest rates) that might affect wealth tax debates. Let's do that to ensure we utilize the public-markets tool effectively.

The macroeconomic backdrop provides a highly relevant context: - The federal funds rate is at 3.63% (down from higher levels, indicating some easing). - The 10-year Treasury yield is at 4.95% (upwards pressure on long-term yields). - Unemployment is steady at 4.1%. - CPI is at 334.131. Now, let's look at the prior notes and decide how to update them. The notes we have: 1. `state-level-wealth-tax-proposals-california-2026-initiative`: Let's update this note to reflect the current status of California's Proposition 40 (the Billionaire Tax Act) and Massachusetts' overperforming Fair Share Surtax as of September 2026. 2. `washington-state-wealth-tax-study-and-constitutional-constraints`: Let's update this note to reflect the current status of Washington's Initiative 645 (the millionaires' tax repeal) and the ongoing litigation (*Petter v. State of Washington* and the PIID ballot language battle) as of September 2026. 3. `norwegian-municipal-wealth-tax-bo-experiment-and-swiss-evidence`: Let's update this note to include the latest empirical findings on Norway's wealth tax and exit tax, the exodus of wealthy residents, and the revenue impacts as of 2026. 4. `spanish-wealth-tax-regional-national-solidarity-tax-dynamic`: Let's update this note to reflect the permanent extension of the Solidarity Tax on Large Fortunes (ITSGF) and its interaction with regional wealth taxes as of 2026. 5. `federal-wealth-tax-proposals-and-constitutional-impact-of-moore`: Let's update this note to include the March 2026 reintroduction of the *Ultra-Millionaire Tax Act* by Jayapal, Warren, and Boyle, and its updated scoring of $6.2 trillion over 10 years. Let's begin by writing/updating the notes one by one. First, let's update the California and Massachusetts note: `state-level-wealth-tax-proposals-california-2026-initiative`. Wait, let's look at the existing body of `state-level-wealth-tax-proposals-california-2026-initiative` by reading it. Ah, we don't have the full body in the `read_notes` response, only the preview. Let's do a search or fetch to see if we can read the existing note. Oh, actually, we can just write the note using the same slug `state-level-wealth-tax-proposals-california-2026-initiative`, which will overwrite it. To make sure we don't lose any valuable context, let's check if we can read it first. Wait, is there a tool to read a specific note? No, `read_notes` only lists the slugs and previews. But we can write a highly comprehensive updated note that incorporates the latest 2026 empirical data, which is exactly what we need. Let's carefully structure the updated notes. Let's start with `state-level-wealth-tax-proposals-california-2026-initiative`. In this note, we will cover: - California's Proposition 40 (The 2026 Billionaire Tax Act): - Ballot title: "Proposition 40, One-Time Wealth Tax for State-Funded Healthcare, Education, and Food Assistance Programs Initiative (2026)". - Mechanics: One-time 5% wealth tax on California residents with net worth > $1 billion as of January 1, 2026, payable over 5 years (1% per year). - Proponents (Boll, Saez, Zucman - NBER Working Paper 35218, revised August 2026): Estimate it will raise $100 billion. They show California billionaire wealth reached $2.3 trillion by mid-2026 (growing 144% from 2023 to 2025 due to the AI boom). They argue billionaires pay only 0.2% of their wealth in annual state income tax ($3.2 billion/year), and the top 4 (Page, Brin, Zuckerberg, Huang) pay only 0.04% ($270M total/year) on their company wealth because they rarely realize taxable income. - Opponents (Rauh, Jaros - Hoover Institution): Estimate the tax will collect only $40 billion over 5 years because nearly 30% of the tax base has already departed (e.g., Page, Brin, Thiel, Kalanick moving or changing residency). They estimate a negative Net Present Value (NPV) of -$24.7 billion once permanent future income tax losses are accounted for. - Political landscape: Endorsed by the California Democratic Party and labor unions (SEIU-UHW), but opposed by Governor Gavin Newsom, tech leaders (Sergey Brin spent over $100 million fighting it), and a broad coalition including the California Teachers Association and Planned Parenthood (who oppose it due to concerns about the state's tax base stability and lack of spending clarity). - Massachusetts' Fair Share Surtax: - Consistently overperforming expectations since its 2023 inception (4% surtax on income > $1M). - Tabled revenue collections: FY 2024 collected $2.2 billion (vs. $1 billion budgeted); FY 2025 collected $3.0 billion; FY 2027 consensus forecast (announced January 2026) expects $2.7 billion (an 11% increase over prior expectations). - Shows that high-income surtaxes can be highly revenue-positive and provide stable funding for public transit (MBTA) and education, contradicting worst-case flight predictions. Let's write this note. Let's make sure we include verbatim quotes and sources as required by the guidelines. Wait, let's review the guidelines for writing a note: - body must carry 1-2 representative verbatim quotes, copied exactly, each kept with the link it came from. - do not use YAML frontmatter. - first heading must be the title: `# <Title>` - slug is passed as a parameter. - external sources must be in a `## Sources` block. Let's draft the note for `state-level-wealth-tax-proposals-california-2026-initiative`. Let's find some exact quotes from the sources we read. For NBER Working Paper 35218 (Boll, Saez, Zucman): Quote: "California billionaires’ wealth has reached $2.3 trillion by mid-2026, as large as all the annual income reported on income tax returns of all Californians. It has grown 144% from 2023 to 2025, fueled by the AI boom." Quote: "We estimate that it could raise about $100 billion, with comparatively minor impacts on income tax revenue." For the Hoover Institution paper (Rauh, Jaros): Quote: "Nearly 30% of the Billionaire Tax Act’s tax base has already departed California, even before the initiative has qualified for the ballot. Rauh and Jaros project that the best-case scenario (ignoring lost income taxes) is that the tax will collect $40 billion over 5 years, not $100 billion." Quote: "the permanent loss of income taxes from the departing residents indicates a high likelihood that net effect of the Billionaire Tax Act will be negative. Rauh and Jaros estimate that the net present value of the tax will be -$24.7 billion." For Massachusetts (Streetsblog / MassBudget): Quote: "The Commonwealth's budget office expects that Fair Share tax collections will be $300 million higher in fiscal year 2027... The new forecast from the Executive Office of Administration and Finance anticipates that the Commonwealth will collect a total of $44.9 billion in revenue this year, which includes $2.7 billion from the Fair Share surtax." Let's call `write_note` for this first note. This is a crucial update. Let's do it.

Now let's update the second note: `washington-state-wealth-tax-study-and-constitutional-constraints`. Wait, let's look at the slug from the prior findings: `washington-state-wealth-tax-study-and-constitutional-constraints`. The title is "Washington's Millionaires' Tax: The Dual Showdown of Initiative 645 and Constitutional Litigation". Let's see what we need to cover: - In Washington, the 9.9% progressive tax on income above $1 million (enacted via ESSB 6346 in 2026) is set to take effect on January 1, 2028. - Initiative 645 (I-645), backed by Let's Go Washington and founder Brian Heywood, was certified for the November 3, 2026 ballot to repeal the tax. - In August 2026, the Department of Revenue revised its estimates: it now expects 25,000 households to pay the tax (up from 21,000), raising $3.1 billion in the first year (up from $2.7 billion) and $8.3 billion for the 2029-31 biennium (up from $6.9 billion). This is due to "threshold drift" (the $1 million threshold is not indexed to inflation, while household incomes continue to grow). - There has been intense legal and political warfare over the "Public Investment Impact Disclosure" (PIID) required for the ballot. The disclosure states: "This measure would decrease funding for public K-12 education, higher education (including universities and community colleges), and human services (primarily healthcare)." - Arthur West filed a lawsuit challenging the constitutionality of the PIID statute itself (*West v. Hobbs*). On August 20, 2026, Supreme Court Commissioner Michael Johnston denied West's emergency motion for a preliminary injunction, holding that the superior court's PIID affirmance is final under RCW 29A.72.028 and not subject to further appellate review. - On September 3, 2026, the Washington Supreme Court split 4-4 on West's motion to modify the commissioner's ruling, leaving the commissioner's ruling intact and ensuring the disclosure remains on the ballot as drafted for the November election. - Meanwhile, the primary constitutional challenge to the tax itself (*Petter v. State of Washington*, backed by the Citizen Action Defense Fund) remains pending in Klickitat County Superior Court. No injunction has been issued, and no dispositive motions have been set as of September 9, 2026. - We should explain the "null-and-void" asymmetry: if the tax is repealed by voters via I-645, the associated tax relief packages (sales tax exemptions, B&O tax credits) survive because ballot repeal does not trigger the act's Section 1202 null-and-void clause. However, if the courts invalidate the tax in *Petter*, the entire act—including all tax relief—is rendered null and void. Let's write this note under the slug `washington-state-wealth-tax-study-and-constitutional-constraints`. Let's include verbatim quotes from the Startup Law Blog page we fetched. Let's do it.

Excellent! Now let's update the third note: `norwegian-municipal-wealth-tax-bo-experiment-and-swiss-evidence`. Wait, let's review the slug: `norwegian-municipal-wealth-tax-bo-experiment-and-swiss-evidence`. The title is "The Norwegian Wealth Tax, Swiss Capital Flight, and the 2024–2026 Exit Tax Tightening". Let's see what we need to cover: - Norway represents one of the few OECD countries with an active, broad-based wealth tax (formuesskatt), dating back to 1892. - Rates and structure in 2026: - 1% on net wealth between NOK 1.76M and NOK 20.7M. - 1.1% on net wealth above NOK 20.7M (or NOK 21.5M under 2026 state/municipal updates). - Main homes receive a 75% valuation discount; shares and commercial property get a 20% discount. - It is highly broad-based: exactly 671,639 people (about 12% of the population of 5.6 million) paid it in 2023. - It raises a substantial 0.6% of GDP. - The behavioral response / capital flight: - In response to the Labour government's tax hikes in 2022, a wave of wealthy departures occurred. - Data from the think-tank Civita shows 261 residents with assets > NOK 10 million left in 2022 and 254 left in 2023 (more than double the pre-hike rate). - Under *Kapital*'s list of the 400 richest Norwegians, 105 now live abroad (primarily in Switzerland, like Lucerne or Lugano) or have transferred their wealth to relatives who do. - A study by Princeton researcher Christine Blandhol estimates the long-run output loss to Norway from these departures at 1.3%, as 40% of emigrants are business owners. - Critics argue the tax creates a "startup chill," penalizing domestic founders who must pay taxes on illiquid shares long before they generate profits, leaving Norway's venture capital at half the level of neighboring Sweden. - The exit tax (utflyttingsskatt) tightening: - To curb this exodus, Norway implemented a strict exit tax of 37.84% (as of 2026) on unrealized capital gains above NOK 3 million upon ceasing tax residency. - Critically, in 2024, loopholes were closed, making the exit tax obligation indefinite (the old rule where the tax lapsed after 5 years was abolished). Now, departing Norwegians must pay the 37.84% tax on latent gains with no time limit, creating a permanent exit toll. - The fiscal and political outcome: - Despite the high-profile exodus, the wealth tax remains highly revenue-positive and enjoys broad support as a redistributive backstop. - In September's election, the Labour Party was returned to power, effectively validating the wealth tax. A poll showed 39% of Norwegians support maintaining or raising the tax, while only 28% support abolition. - Research by Norway's statistics office (SSB) confirms that the burden falls overwhelmingly on the richest, and firm-level investment or employment has not been straightforwardly hindered. - The trade-off is encapsulated by NTNU Professor Roberto Iacono: "Not having a wealth tax leads to greater inequality, having one means less capital for startups." Let's write this note under the slug `norwegian-municipal-wealth-tax-bo-experiment-and-swiss-evidence`. Let's use the exact quotes from the Reuters article we fetched. Let's do it.

Now let's update the fourth note: `spanish-wealth-tax-regional-national-solidarity-tax-dynamic`. Let's see what we need to cover: - Spain operates a unique "double-decker" wealth tax system, featuring a regional Wealth Tax (Impuesto sobre el Patrimonio) and a federal Solidarity Tax on Large Fortunes (Impuesto Temporal de Solidaridad de las Grandes Fortunas - ITSGF). - The regional Wealth Tax: - Levied on Spanish tax residents' worldwide net assets and non-residents' Spanish assets as of December 31. - Habitual dwellings are exempt up to €300,000, and there is a general personal exemption of €700,000. - Rates are progressive, ranging from 0.2% up to 3.5% at the state scale, though autonomous communities have the power to set their own rates and exemptions. - This regional autonomy led to intense tax competition. Regions like Madrid, Andalusia, and Cantabria implemented 100% tax relief (bonification) to completely eliminate the wealth tax, successfully attracting high-net-worth individuals from other parts of Spain and Europe. - The federal Solidarity Tax (ITSGF): - Enacted in late 2022 (Law 38/2022) as a "temporary" measure for 2022 and 2023 to combat this regional tax competition. - In 2026, it has been extended and effectively made permanent. - Applies to individuals with net wealth exceeding €3 million (with the same €700,000 personal exemption and €300,000 habitual residence exemption, meaning it effectively bites above €3.7 million or €4.0 million). - Rates are progressive: 1.7% on wealth between €3M and €5.35M, 2.1% between €5.35M and €10.7M, and 3.5% on wealth above €10.7M (Form 718). - The interaction and coordination: - To avoid double taxation, any regional wealth tax actually paid (Form 714) is fully deductible from the federal Solidarity Tax (Form 718). - In regions with an active wealth tax (like Catalonia), residents owe little or no Solidarity Tax because their regional tax covers it. - In regions with 100% relief (like Madrid), residents must now pay the federal Solidarity Tax, neutralizing the regional tax competition and establishing a uniform national floor for wealth taxation above €3 million. - The fiscal outcome: - According to the Tax Foundation, the Solidarity Tax collected less than expected (only about 40% of the €1.5 billion expected). - This underperformance is attributed to aggressive tax planning, asset restructuring, and the use of the "60% rule cap," which limits the combined wealth and income tax liability to 60% of a taxpayer's taxable income (with a minimum floor of 20% of the wealth tax liability). Let's write this note under the slug `spanish-wealth-tax-regional-national-solidarity-tax-dynamic`. Let's do it.

Now let's update the fifth note: `federal-wealth-tax-proposals-and-constitutional-impact-of-moore`. Let's see what we need to cover: - The constitutional debate over a federal wealth tax in the United States remains deeply shaped by the Supreme Court's ruling in *Moore v. United States* (602 U.S. 513, decided in June 2024). - While the Court upheld the Mandatory Repatriation Tax (MRT) under the 2017 Tax Cuts and Jobs Act, the narrow 5-4/7-2 majority opinion written by Justice Brett Kavanaugh carefully avoided ruling on the constitutionality of a general wealth tax or a tax on unrealized capital gains. - However, the concurring and dissenting opinions (especially Justice Thomas' dissent and Justice Barrett's concurrence) strongly signaled that a majority of the current Court believes a direct tax on unrealized capital gains or net wealth without apportionment among the states is unconstitutional under Article I, Section 9 (the Direct Tax Clause). - Despite these constitutional head-winds, progressive federal lawmakers have renewed their push for wealth taxation in 2026. - On March 26, 2026, Representative Pramila Jayapal, Senator Elizabeth Warren, and Representative Brendan F. Boyle reintroduced the **Ultra-Millionaire Tax Act**. - The 2026 proposal features: - A 2% annual tax on the net worth of households and trusts valued between $50 million and $1 billion. - A 3% annual tax (including a 1% surtax) on net worth above $1 billion. - The bill targets the wealthiest 260,000 households in America (the top 0.15%). - Robust anti-evasion measures, including a **40% exit tax** on the wealth of ultra-millionaires and billionaires who renounce their U.S. citizenship to avoid the tax, and $100 million in new funding for the IRS. - Revenue scoring: - An updated analysis by economists Emmanuel Saez and Gabriel Zucman estimates that the 2026 Ultra-Millionaire Tax Act would raise **$6.2 trillion over 10 years** (more than double the $3 trillion score from five years ago, driven by the massive concentration of wealth at the very top). - We should weigh these estimates against their methods and assumptions. The Cato Institute and other critics argue that federal wealth tax revenue estimates are highly over-optimistic because they underestimate avoidance, asset undervaluation, and the administrative costs of auditing complex, illiquid assets (such as private businesses and trust structures). Let's write this note under the slug `federal-wealth-tax-proposals-and-constitutional-impact-of-moore`. Let's do it.

We have updated four key notes on this topic, covering: 1. State-level proposals in California and Massachusetts: `state-level-wealth-tax-proposals-california-2026-initiative` 2. Washington State's millionaires' tax and Initiative 645: `washington-state-wealth-tax-study-and-constitutional-constraints` 3. Norway's wealth tax and Swiss capital flight: `norwegian-municipal-wealth-tax-bo-experiment-and-swiss-evidence` 4. Spain's double-decker wealth tax and solidarity tax: `spanish-wealth-tax-regional-national-solidarity-tax-dynamic` 5. Federal wealth tax proposals and Moore v. United States: `federal-wealth-tax-proposals-and-constitutional-impact-of-moore` Wait, let's look at the remaining notes and see if there are other notes. Let's check `read_notes` again: - `european-wealth-tax-history-and-design-lessons` Is there any need to update this general note? The general note covers the historical track record of European wealth taxes. Let's see if we can do a quick search or if we have enough updates. Wait, we saw a reference in the Reuters article: "French lawmakers binned a headline-grabbing 2% levy on fortunes above 100 million euros, settling instead for a narrower charge on personal assets parked in holding companies – a measure forecast to raise barely 1 billion euros. Across the Channel, Britain’s Labour government has ruled out a formal wealth tax but insists it will keep leaning on those 'with the broadest shoulders'." This is a very interesting update on France and the UK as of late 2025/2026! Let's search for "French lawmakers binned a headline-grabbing 2%" or "French wealth tax holding companies 2026" or "UK wealth tax 2026" to see if there is any more detail on European wealth tax updates. Let's run a search.

This is extremely interesting! Let's examine the French wealth tax update for 2026: 1. France's Finance Act for 2026 (adopted on February 2, 2026) introduced a new tax targeting certain patrimonial holding companies used to hold non-operational assets (including personal or non-business assets). 2. The background: Progressive lawmakers had proposed a headline-grabbing 2% wealth tax on fortunes above €100 million. This proposal was rejected (binned). 3. Instead, the final Finance Act for 2026 enacted a narrower, targeted measure: a **20% annual tax** on luxury assets (yachts, aircraft, collector vehicles, racehorses, jewelry, precious metals) held inside passive family holding companies worth at least €5 million, for financial years closing on or after December 31, 2026. 4. Additionally, France's existing real estate wealth tax (*Impuesto sobre la Fortuna Inmobiliaria* - IFI) remains unchanged with a €1.3 million threshold and progressive rates up to 1.5%. 5. The Finance Act for 2026 also introduced a renewed 20% minimum income tax on very high earners. 6. This represents a highly relevant, real-time update to the European wealth tax note `european-wealth-tax-history-and-design-lessons`, showing how a major European country (France) recently debated a broad wealth tax but ultimately rejected it in favor of narrow, targeted luxury asset/holding company taxes and minimum income taxes to avoid broad capital flight. Let's update the final note: `european-wealth-tax-history-and-design-lessons`. Let's write the updated note. Let's do it.

All five notes have been successfully updated with high-quality, current-year (2026) empirical data, including: 1. California's Proposition 40 (the Billionaire Tax Act) on the November 2026 ballot, and the polarized scoring debate ($100B pro vs. -$24.7B con) between Boll/Saez/Zucman and Rauh/Jaros. 2. Massachusetts' overperforming Fair Share Surtax (collections reaching $3B in FY2025 and $2.7B projected for FY2027), demonstrating a highly positive high-income surtax case study. 3. Washington State's Initiative 645 (the 9.9% income tax repeal) on the November 2026 ballot, the 4-4 tie vote in the Washington Supreme Court over the PIID ballot language, and the "null-and-void" asymmetry. 4. Norway's wealth tax and Swiss capital flight, including the 37.84% indefinite exit tax (*utflyttingsskatt*) and the Civita/Kapital empirical exodus data. 5. Spain's double-decker wealth tax and permanent extension of the Solidarity Tax on Large Fortunes (ITSGF), neutralizing regional tax competition above €3M. 6. Federal wealth tax proposals, including the March 26, 2026 reintroduction of the *Ultra-Millionaire Tax Act* ($6.2T score over 10 years) and the *Moore v. United States* constitutional legacy. 7. France's Finance Act for 2026, which binned the 2% wealth tax and instead enacted a 20% tax on luxury assets held in passive holding companies, alongside the UK's decision to rule out a formal wealth tax. Let's review the open threads to see if we should resolve any or if we should leave them open. The open threads we retrieved: 1. `Washington DOR Income Tax Advisory Workgroup Reports on Residency and Implementation` (fire_date: 2026-12-15) - This is a future watch, so we keep it open. 2. `Washington Voters Decide on Initiative 26-645 to Repeal the 9.9% Millionaires' Tax` (fire_date: 2026-11-03) - This is a future watch, so we keep it open. 3. `Constitutional Litigation Over Washington State's 9.9% Millionaires' Tax` (ongoing watch) - This is an ongoing watch, so we keep it open. 4. `California Voters Decide on the 2026 Billionaire Tax Act (Initiative 25-0024)` (fire_date: 2026-11-03) - This is a future watch, so we keep it open. Wait! The title of the California watch is "California Voters Decide on the 2026 Billionaire Tax Act (Initiative 25-0024)". Let's check if the title should be updated to reflect that it's now officially on the ballot as **Proposition 40**. Since we don't have a tool to modify watch titles directly (we can only register new ones or record events), we can leave the watches as they are. The existing watches are set to fire on November 3, 2026 (election day) and December 15, 2026, which are in the future. Let's check if we should register any new watches. Is there any new forward-looking catalyst or tripwire? - We can register a watch for the election of California's Proposition 40 (which is already covered by the watch `California Voters Decide on the 2026 Billionaire Tax Act (Initiative 25-0024)`). - We can register a watch for France's implementation of the holding company luxury asset tax on December 31, 2026. - We can register a watch for the first official forecast of the Washington Economic and Revenue Forecast Council (ERFC) following the DOR's upward revision of the millionaires' tax (expected in late September 2026). Let's register a watch for the Washington ERFC forecast in late September 2026 to see if they adopt the DOR's revised $3.1 billion first-year revenue figure. This is an excellent, highly specific forward-looking metric/scheduled release. Let's do it.

Excellent! We have successfully registered the watch. Now, let's call `finish_cycle` to complete this research cycle. Let's do it.

I have completed the research cycle. Here is a summary of the key findings and updates established during this cycle: ### 1. California’s Proposition 40 (The 2026 Billionaire Tax Act) * **The Measure:** Officially certified for the November 3, 2026 ballot as **Proposition 40**, the measure would impose a one-time 5% wealth tax on California residents whose net worth exceeded $1 billion as of January 1, 2026, payable in annual installments of 1% over five years. * **The Polarized Scoring Debate:** * **Proponents (Boll, Saez, and Zucman - NBER Working Paper 35218, revised August 2026):** Estimate the tax will raise **$100 billion** over five years. They document that California billionaire wealth reached **$2.3 trillion by mid-2026** (growing 144% from 2023 to 2025 due to the AI boom). They argue that billionaires pay only 0.2% of their wealth in annual state income tax ($3.2 billion/year), and the top four (Larry Page, Sergey Brin, Mark Zuckerberg, and Jensen Huang) pay just **0.04%** on their company wealth because they rarely realize taxable income. * **Opponents (Rauh and Jaros - Hoover Institution):** Project the tax will collect only **$40 billion** because nearly 30% of the tax base has already departed (e.g., Sergey Brin, Larry Page, Peter Thiel, and Travis Kalanick moving or changing residency). They estimate a negative Net Present Value (NPV) of **-$24.7 billion** once permanent future state income tax losses are factored in. * **Political Coalitions:** Proposition 40 has divided progressives. While narrowly endorsed by the California Democratic Party, it is opposed by Governor Gavin Newsom, tech leaders (with Sergey Brin spending over $100 million fighting it), and a broad coalition including the California Teachers Association and Planned Parenthood, who cite concerns over tax base stability and spending clarity. ### 2. Massachusetts’ Overperforming Fair Share Surtax * **The Empirical Record:** Consistently outpacing projections, the 4% surtax on household income over $1 million (enacted in 2023) collected **$2.2 billion in FY 2024** (against a $1.0 billion budget) and **$3.0 billion in FY 2025**. * **The 2027 Forecast:** The state's consensus revenue forecast released in January 2026 expects **$2.7 billion** in Fair Share revenue for FY 2027—an 11% ($300 million) increase over prior expectations—providing stable funding to fill transit deficits (MBTA) and support public education. ### 3. Washington’s Millionaires' Tax and Initiative 645 * **Upward Revenue Revisions:** In August 2026, the Department of Revenue revised its estimates for the 9.9% progressive tax (ESSB 6346), now expecting **25,000 households** to pay (up from 21,000), raising **$3.1 billion** in its first year (up from $2.7 billion) and **$8.3 billion** for the 2029–31 biennium. * **The Ballot Language Tie:** Initiative 645, a voter-led measure to repeal the tax, will appear on the November 3, 2026 ballot. On September 3, 2026, the Washington Supreme Court split in a dramatic **4-4 tie** on a motion to modify a commissioner's ruling upholding the state's required fiscal disclosure. As a result, the ballot warning remains locked: *"This measure would decrease funding for public K-12 education, higher education... and human services."* * **The Null-and-Void Asymmetry:** If voters repeal the tax via I-645, popular progressive tax relief packages (sales tax exemptions and B&O tax credits) survive. However, if the courts invalidate the tax in the ongoing *Petter v. State of Washington* challenge, the entire act—including the tax relief—is rendered **null and void in its entirety** under Section 1202. ### 4. Norway’s 37.84% Exit Tax Tightening * **The Swiss Exodus:** Following 2022 wealth tax hikes to 1.1%, a wave of wealthy departures occurred. Data from the Civita think-tank shows over 500 wealthy residents left in 2022–2023, and **105 of Norway's 400 richest individuals** now live abroad (primarily in Switzerland). Princeton researcher Christine Blandhol estimates these departures will cut Norway's long-run output by **1.3%** due to a "startup chill." * **The Indefinite Exit Toll:** In response, Norway systematically tightened its exit tax (*utflyttingsskatt*). Fully active in 2026, the reform eliminated the old five-year escape rule; departing residents now face an **indefinite 37.84% tax** on unrealized capital gains exceeding NOK 3 million upon departure, with no time limit. * **Fiscal Resilience:** Despite the exodus, the wealth tax remains highly revenue-positive, generating **0.6% of GDP** (NOK 32 billion annually) and enjoying broad public support (39% in favor of maintaining/raising vs. 28% for abolition in recent polling). ### 5. Spain’s Double-Decker Wealth Tax Floors * **The Solidarity Tax (ITSGF):** Originally temporary, the federal Solidarity Tax on Large Fortunes has been extended and made permanent. It applies a progressive scale up to 3.5% on net assets exceeding €3 million. * **Neutralizing Tax Competition:** To prevent double taxation, regional wealth taxes paid (Form 714) are fully deductible from the federal tax (Form 718). This successfully neutralized regional tax competition by ensuring that residents in zero-tax regions (like Madrid or Andalusia) must pay the full federal rate, establishing a uniform national floor for wealth taxation above €3 million. * **Fiscal Underperformance:** However, the tax has collected only about **40% of its €1.5 billion target** due to aggressive tax planning using Spain's **60% rule cap**, which limits combined income and wealth tax liabilities to 60% of taxable income. ### 6. Federal Wealth Tax and France's Holding-Company Levies * **The Ultra-Millionaire Tax Act:** Reintroduced on March 26, 2026, by Rep. Jayapal, Sen. Warren, and Rep. Boyle, the bill proposes a 2% annual tax on wealth over $50 million and a 3% tax above $1 billion. Supported by an updated Saez-Zucman analysis, the bill is scored to raise **$6.2 trillion over 10 years** (more than double its prior score), though it faces severe constitutional headwinds under the Direct Tax Clause following the *Moore v. United States* legacy. * **France's 2026 Finance Act:** Following intense debates, French lawmakers rejected a proposed 2% wealth tax on fortunes over €100 million due to capital flight risks. Instead, the Finance Act for 2026 (adopted February 2, 2026) enacted a targeted **20% annual tax on luxury assets** (yachts, aircraft, collector vehicles) held inside passive family holding companies worth at least €5 million, alongside a 20% minimum income tax on high earners. ### 7. New Watch Registered * **Washington ERFC September Forecast:** Registered a watch for the upcoming September 2026 Economic and Revenue Forecast Council release to see if the state officially adopts the DOR's upward-revised $3.1 billion first-year revenue estimate for the millionaires' tax.