This morning, the Census announced that the SPM child poverty rate was 13.4% in 2025, down 0.1 pp from 2024. Today we're launching the Child Poverty Impact Dashboard: a tool to analyze how reforms can affect this rate across all 50 states and DC. policyengine.org/us/child-po…

PolicyEngine at @theiariw Brussels this week: two papers, two discussions, and a free workshop Thursday 27 Aug with CAPE and BEAMM — talks, a live demo, and a roundtable with Belgian policy institutions. Register: policyengine.org/iariw-2026

PolicyBench tests how accurately AI models compute US taxes and benefits. Two new rows: Ox Alpha, a cloaked preview model with no maker named, debuts fourth of 32 at 84.2% of answers within $1. @grok 4.6 debuts eighth at 82.8%, 1.9 points past Grok 4.5. policybench.org

.@thinkymachines' first model debuts on PolicyBench as the strongest American open-weight model: Inkling lands #4 of 29, computing 83.8% of US tax and benefit amounts within $1 — ahead of GPT-5.5 and every Claude. @Alibaba_Qwen's new Qwen3.8-Max debuts #25 at 71.5%. policybench.org

.@AnthropicAI's Claude Opus 5 debuts on PolicyBench at #8 of 27 — 79.8% of US tax and benefit amounts within $1, 0.1 points behind Claude Fable 5 and +7.2 over Opus 4.8, the second-biggest version jump we've measured. policybench.org

New from @BudgetHawks, built on PolicyEngine microsimulation: New Approaches to Social Security Benefit Taxation — 16 reform options scored year by year through 2100 on the 2026 Trustees baseline. crfb.org/papers/new-approach…

1/ We asked 28 frontier LLMs — GPT, Claude, Gemini, Grok, DeepSeek, Qwen, Kimi, GLM, MiniMax — for the same 26 economic parameters, 15 times each. 10,920 elicitations, every prompt and response in a public repo. The headline: where economics has settled, the models have settled — and where it's still arguing, the models still argue. That unresolved part moves the US optimal-tax answer by about nine points. policyengine.org/ai-beliefs

New from PolicyEngine: AI beliefs — elicited economic parameters from 28 frontier language models, 15 runs each, over 26 US-scoped quantities. Pooled centers, 90% intervals, and run-level data for every cell, with literature review ranges alongside. policyengine.org/ai-beliefs

.@Kimi_Moonshot's Kimi K3 debuts #2 of 25 on PolicyBench — the first open-weight model to crack our top ten. 86.2% of US tax and benefit amounts within $1, no tools, +21.6 points over Kimi K2.6: the biggest version jump we've measured.

PolicyEngine at the 10th International Microsimulation Association World Congress in Brussels last week: · Maria Juaristi on L0-regularised calibration for subnational microsimulation populace.dev/papers/l0 · @vahiidahmadi on an open firm-level model of the UK VAT registration threshold populace.dev/papers/firms · @MaxGhenis with a hands-on tutorial — build reforms in the browser and in Python policyengine.org/tutorial

GPT-5.6 joins PolicyBench, our benchmark of how accurately AI computes US taxes and benefits (no tools, scored against PolicyEngine): Sol #1 of 23 — 88.7% within $1 (prior best 83.5%) Luna #2 — 84.5% Terra #4 — 83.4% policybench.org

PolicyBench now scores 20 AI models on how accurately they compute US taxes and benefits — adding Claude Fable 5, Claude Sonnet 5, and five open-weight models: DeepSeek, Qwen, GLM, MiniMax, and Kimi. GPT-5.5 leads, Fable ranks #2, and DeepSeek v4-pro tops the open-weight models.

Last week, @GovDanMcKee signed the Rhode Island Fiscal Year 2027 budget, which includes a new refundable Child Tax Credit. Beginning in 2027, taxpayers can claim $330 for each child under the age of 19. Using our RI CTC calculator, we analyzed the impact of this program.

Can a language model compute a household’s taxes and benefits from the prompt alone — no tools, no lookups? We tested 13 frontier models against PolicyEngine on 100 representative US households and 18 tax and benefit outputs. New benchmark: PolicyBench. policybench.org

Earn a dollar more, take home less. Benefit cliffs happen when a household loses more in benefits than it gains in earnings. CliffWatch shows where, when, and how — across earnings levels and US states. Live demo Fri May 29, 1pm ET → us06web.zoom.us/meeting/regi…

New @UHEROnews analysis uses PolicyEngine to simulate Hawaii's childcare credit bills — first the direct household effect of the expanded CDCC, then the integrated CDCC, EITC, SNAP, WIC, and state income tax impact when a second earner enters the workforce in response.

Today at 11 AM at EAGxDC: why frontier LLMs miss basic tax and benefit math, what changes when AI agents call an open simulator, and where our new initiatives like PolicyBench and the Economic Parameter Atlas come in.

We added a ton of ingredients to @ThePolicyEngine cauldron last month: - 1,039 PRs merged (7× April 2025, 2× March 2026) - 341,318 source-code lines changed - 19 new repos Childcare subsidy rules, Forbes 400, better reproducibility - all make our models more accurate & useful.