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Simulating futures
to build the one we want.

I build open-source software that computes what the law says, measures what it does, and projects what happens next.

Max Ghenis CEO, The Axiom Foundation & PolicyEngine · Washington, DC
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Rules what the law says — exact, cited, computable
Impacts what it does — for any household, for whole populations
Projections what happens next — modeled openly, revised as law changes
Work
Founder & CEO · 2026—

The Axiom Foundation

Publishes the law as open, verified code — every value citing its statute, every clause carrying its effective date, every encoding checked against independent implementations. Launches publicly July 28; PolicyEngine becomes its first and most demanding consumer.

axiom-foundation.org →
Co-founder & CEO · 2021—

PolicyEngine

Free, open-source software that computes taxes and benefits for any household and simulates reforms across whole populations. Policymakers, researchers, and benefit navigators use it in the US, UK, and Canada.

policyengine.org →
AI eval

PolicyBench

Open benchmark scoring AI models on tax and benefit law, graded against exact calculations.

 Microdata

Populace

Calibrated survey microdata for policy simulation — national to local, fully reproducible.

 macOS

OpenMessage

macOS Google Messages client that gives coding agents access to your texts.

 Monte Carlo

MacKenzie Scott's giving, in QALYs

GiveWell-style Monte Carlo model of $26.3B in giving, running entirely in your browser.

 Python

microdf

Pandas extensions for weighted survey microdata, used across PolicyEngine's models.

 VS Code

TerminalGrid

VS Code extension for keyboard-driven terminal grids, built for agentic coding.
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Writing
Testing California's bond funds against the billionaire tax odds Prediction markets have priced California's Proposition 40 for almost a year, and a fund of California municipal bonds has not moved with the odds by any amount I could detect. Before November 3, I registered a test that pools ballot measures across states. What do forecasters say they don't know? Professional forecasters in the US and euro area have reported full probability distributions for decades. I pooled every one into a tracker and two working papers, and read what they say about growth in the AI era. A year of ChatGPT is a fifth of a beer I built an interactive that prices drinks in AI queries — and lets you flip the accounting scope and the workload unit that make published AI water numbers differ by 100x. MacKenzie Scott's giving, in QALYs An interactive cost-effectiveness model for MacKenzie Scott's $26B in philanthropy — and the AI prompts that built it.
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Research
2024 Enhancing survey microdata with administrative records Microsimulation dataset construction. Presented at NTA 2024. 2025 What can LLMs tell us about the ETI? With Jason DeBacker. How language models perceive behavioral responses to tax policy.
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