February 4, 2026
Sliders, spreadsheets, and spooked billionaires
Show HN: Interactive California Budget (By Claude Code)
Billionaire tax slider sparks flame war as Californians nitpick every dollar
TLDR: A new interactive tool lets users toggle a one‑time 5% billionaire wealth tax in California, modeling up to ~$58B in revenue and potential billionaire flight. Commenters clash over overspending, a suspicious $8B higher‑ed jump, Prop 98’s K‑12 mandate, and demand open‑source code plus clearer inflation‑adjusted numbers.
An HN dev just dropped an interactive California budget toy that lets you toggle a one‑time 5% wealth tax on billionaires—theoretical max: a jaw‑dropping ~$58B—and the comments instantly turned into a fiscal food fight. The tool also plays out how many billionaires might bail (10–25% if you believe the research), who really pays income and corporate taxes, and why Medi‑Cal costs keep rising even as enrollment is projected to fall.
But the community’s main character? The comments. One camp is shouting “we overspend,” with johnsmith1840 demanding real‑world forecasts and confidence ranges like it’s earnings season. Another is calling out the numbers: bradlys flagged a “magically” $8B jump in higher ed that doesn’t match subcategories and could be half the deficit, while kyboren wants a constant‑vs‑nominal toggle and more history to show how Prop 98 locked in big K‑12 growth. Meanwhile, codybontecou drops a meta‑burn: let Claude use Anthropic’s new “frontend design” tricks for prettier charts.
The vibe swings from policy wonk to popcorn hour. Some readers treat the “billionaire flight” slider like a panic meter, others just want the code public so they can audit every cell. It’s equal parts tax theory, data‑nerd CSI, and UI feedback session—aka classic Hacker News drama, now with billionaire stakes and budget sliders for dessert.
Key Points
- •Proposed one-time 5% wealth tax on net worth above $1B could theoretically raise ~$58B from ~186 CA billionaires with ~$1.16T total wealth (Forbes 2024).
- •Actual collections depend on wealth valuation methods, legal challenges, and payment timelines.
- •Migration modeling cites Young et al. (2016): ~2.2% millionaire migration per 1pp tax increase; a 5% one-time tax could trigger a 10–25% billionaire exodus.
- •Top 1% pays ~45% of California Personal Income Tax; billionaires’ share is outsized due to capital gains concentration.
- •Medi-Cal General Fund costs are rising per enrollee despite projected caseload decline from ~15M to ~12M by 2029–30.