[MaxGhenis]

US newsletter for Thursday, October 29, the day before the Prop 40 webinar.

Sent 2026-10-29 at 20:05 UTC (4:05pm ET) to 762 non-UK subscribers (Mailchimp 8a11e388cb, segment COUNTRY is not United Kingdom), on Max's go in chat: "send it to us (or non-uk), looksgood" (decision d2176). The file at 5e91588 is what went out. Archive: https://us5.campaign-archive.com/?u=e5ad35332666289a0f48013c5&id=8a11e388cb

The seven dashboard links point at ballot-measures-2026.vercel.app/us/ballot-measures-2026/..., because policyengine.org/us/ballot-measures-2026 still returned 404 at send time (policyengine-app-v2 #1415, the proxy, is a draft). Both addresses serve the same deployment, so the vercel.app links keep working after #1415 merges.

The last US newsletter sent was September 8 (Mailchimp d19a2833b4). The September 30 draft (#26, Mailchimp b835a77fb1) never went out, so its lead (the graded poverty prediction) folds in here in short form. Once this edition sends, #26 can close as superseded.

Sections

• Lead: tomorrow's webinar, "Why the Prop 40 revenue estimates differ", Friday, October 30, noon PT / 3pm ET, with Max Ghenis, David Trimmer and Fernando Hoces de la Guardia. Copy follows the app-v2 events listing (app/src/data/events.json), which dropped the no-position line and the days-before-the-vote line (app-v2 #1418, #1419). Register button: the Zoom registration link from the calendar event.
• Chart: the calculator's "What separates the published estimates" bridge, screenshotted from policyengine.org/us/california-wealth-tax on Forbes data as of 2026-10-29 (assets/images/prop40-bridge-2026-10-29.png, pinned at 991a80d).
• What the calculator finds: the first three bullets come from the live page on 2026-10-29 (statutory one-time revenue $117.6B; Berkeley +$103.1B and Hoover −$34.1B NPV; income tax counted −$66.4B, legal challenges −$53.7B, residency −$23.2B), to match the chart. The fourth comes from the working paper on the October 23 snapshot ($4.55B divided by wealth gives the four largest $1,785M against $252M from filings). The paper link points at the copy the calculator hosts (/us/california-wealth-tax/papers/web/), per Max: not posted to SSRN yet.
• Six more ballot measures (added at Max's request, on the model of the 2024-11-04 "Final Election Update"): David Trimmer's 2026 ballot measures dashboard (PolicyEngine/ballot-measures-2026, results manifest 2026-10-28, policyengine-us 2.72.4, complete and not synthetic). Each measure gets one line: what passing it does, the dashboard's headline figure and the official figure with its source, with scope differences stated (Amendment 87's official figure includes C corporations and a fiscal year; North Dakota's covers pre-K; South Dakota is a conditional scenario, with its 29,055 matching the DSS July 2024 to June 2025 monthly average, per the README's scaling). Links use the dashboard's live address (see the note above).
• BLS seminar, October 8: facts from policyengine-slides slideshows/bls-taxsim-2026 (README and config: Suitland, the three presenters, the topics). The 100+ attendance, about half in person, comes from the host's thank-you email of October 9.
• Poverty prediction: from /us/research/2025-spm-poverty-prediction and /us/research/2025-supplemental-poverty-measure (the senior miss falls from 0.76 to 0.09–0.26 points and the child miss from 0.92 to 0.6; the copy rounds these to 0.8, 0.1–0.3 and "about a third"), plus the September 15 recording and the Child Poverty Impact Dashboard.
• PolicyBench: the October 14 board (50 models; GPT-6 Sol 95.2%; ranks 9 and 10 at 90.1%) and the September 22 reference-audit note (20 confirmed defects in policyengine-us 1.755.4). Max's October 14 Open Source Summit talk and the October 26 Aspen session mirror Axiom's For All Nº 002 (TheAxiomFoundation/newsletters editions/2026-10-29.html).
• JOSS paper: from /us/research/policyengine-joss-paper (DOI 10.21105/joss.11115). The message house's do-not-claim on "peer-reviewed" exits once the paper has a DOI, and it now has one.
• Model updates (the April 15 and May 19 format, at Max's request): "more than 500" counts policyengine-us PRs merged since 2026-09-08 (534 on 2026-10-29). US model bullets come from the policyengine-us changelog, 1.825.0 to 2.77.0. The copy states these as additions since September 8: 26 states with regular heating assistance added (Ohio and Nebraska partial; 2.22.0 to 2.76.0); 17 more states with SSI state supplements (2.44.0 to 2.58.0); student loan repayment plans (2.61.0, 2.62.0, 2.65.0); NYC income tax elimination credit (2.35.0); 12-month Medicaid postpartum in 50 jurisdictions (2.67.1); FY2027 SNAP (2.15.7); 2027 COLA (2.49.13); SNAP child support for 46 jurisdictions (2.11.4); retirement exclusions in 20 states (2.6.2). Also 2.63.3 (2027 premium tax credit table). US data bullets: microcosm #1044 (2025 ASEC, default pool 2023 to 2025), #1043 with #1041 (117th to 119th district mapping through block plans, North Carolina fix), #923 (ACS usual hours in local-area data).
• Axiom: the PBIF Spring 2026 cohort, as Axiom's newsletter words it, with no award figure or state.
• Coming up: APPAM, Thursday, November 5, 10:15am. The program lists the session's submission type as Roundtable.

After review

Max asked that nothing mirror the Axiom newsletter's wording. 2461090 rewrote the BLS lead, the PolicyBench heading and paragraph, the Nava and Aspen sentences and the Axiom section. A 4-word comparison with For All's 2026-09-10, 2026-10-08 and 2026-10-29 editions now matches only proper names and footer merge tags. 5e91588 repointed the dashboard links and aligned the PolicyBench audit sentence with the note ("flagged reference answers against statutes and regulations").

Template

US editions keep the light US layout from September 8 and the held September 30 draft (teal masthead rule, "View in browser", "Also in this issue", "Forward to a colleague"), not the dark UK template that CLAUDE.md describes. Images are pinned to commit SHAs. The template has no gradients, so the Outlook fallback note does not apply. The preheader text must match the campaign preview: "Tomorrow at noon PT, we put the Berkeley and Hoover estimates of Prop 40 in one open model and show where they part ways."

Review

An independent GPT-6.1 Sol review of dc6efb9 returned SHIP AFTER FIXES with nine findings. 6e69c24 applies them:

1. The measure description now separates the residency date (January 1) from the valuation date (December 31, 2026), and gives the rate ramp from $1 billion to $1.1 billion and the exclusion of directly held real property (california-wealth-tax README).
2. The heating and SSI counts read as additions since September 8 ("17 more states").
3. The Register button is now a table cell carrying the padding and background, so classic Outlook keeps its shape.
4. Three details had no source the reviewer could open; each one stays, on a source we hold. The host's October 9 email gives the BLS attendance (100+, about half in person). The calendar event runs 3 to 4pm ET, giving 60 minutes, and its description says the session is recorded and will be posted.
5. The senior poverty miss now reads "from 0.8 points to between 0.1 and 0.3", where "two-thirds or more" overstated the low end.
6. APPAM: "panel" became "roundtable".
7. The eyebrow labels keep text-transform: uppercase, matching the sent September 8 and May 19 US editions. Their source text is in sentence case.
8. Active voice: alt text, the gap bullet ("account for"), two headings ("How our 2025 poverty prediction scored", "A peer-reviewed paper on our Python package"), the model and Axiom paragraphs, and the footer ("We sent this email to").
9. The contents line names the section "From the Axiom Foundation".

Rounds 2 and 3, same reviewer, on the sections added after Max's later asks:

• Round 2, ballot section (f0c2a82), SHIP AFTER FIXES. It confirmed all six headline figures and the 20,694 coverage-gap figure against metrics.csv, and all seven dashboard paths against the dashboard's routes. Fixed in aec19c9:
  • South Dakota now names the Attorney General/sponsor disagreement, the scenario dates, the modeled year and the enrollment basis.
  • Proposition NN now says where the retained revenue goes.
  • Initiative 645's statutory bar is limited to taxes on individual income.
  • North Dakota's official range is labeled pre-K through 12.
  • The intro says "compares … with the official figures".
  • Kept: the uppercase eyebrow, as in round 1.
• Round 3, model updates (24d3364), SHIP AFTER FIXES. Fixed in 03bc70f:
  • Every bullet now names its actor.
  • The retirement fix is described as "retirement income tax rules in 20 states", because some of the 20 states changed credits.
  • The data bullets describe the pipeline change itself.
  • The state income-band bullet is dropped: microcosm #1102 adds the IRS figures, but no calibration or release has used them yet.

Re-rendered at 03bc70f with headless Chromium at 700px and 375px: no broken images and no horizontal scroll. At send (5e91588), all 31 unique URLs returned 200.

🤖 Generated with Claude Code

[MaxGhenis]

Merging as the record of what went out (sent 2026-10-29 20:05 UTC, Mailchimp 8a11e388cb, 762 non-UK recipients, on Max's go in chat). Head 5e91588. Gates: all 5 checks pass; MERGEABLE; GPT-6.1 Sol reviews r1 (dc6efb9), r2 (f0c2a82, ballot section) and r3 (24d3364, model updates) each returned SHIP AFTER FIXES, and the fixes are in 6e69c24, aec19c9 and 03bc70f. Later commits are Max-requested rewording (2461090) and the dashboard link repoint (5e91588; all 31 URLs 200 at send). Merge commit, per this repo's convention, so the pinned image commit 991a80d stays on main.