Max Ghenis
@maxghenis.bsky.social
Co-founder and CEO of @policyengine.org
Between per-provision selection, animated yearly trends, constituency maps, and real-time personalized *full-lifecycle* effects, this is our most comprehensive policy analysis tool yet.
See the impact of the UK's most substantial budget in years: www.policyengine.org/uk/autumn-bu...
See the impact of the UK's most substantial budget in years: www.policyengine.org/uk/autumn-bu...
Our complete analysis of the UK Autumn Budget 2025 is now live.
New interactive dashboard lets you explore how all 9 provisions interact—by income decile, constituency, and year through 2030-31.
Explore: policyengine.org/uk/autumn-budget-2025
New interactive dashboard lets you explore how all 9 provisions interact—by income decile, constituency, and year through 2030-31.
Explore: policyengine.org/uk/autumn-budget-2025
December 11, 2025 at 1:13 AM
Between per-provision selection, animated yearly trends, constituency maps, and real-time personalized *full-lifecycle* effects, this is our most comprehensive policy analysis tool yet.
See the impact of the UK's most substantial budget in years: www.policyengine.org/uk/autumn-bu...
See the impact of the UK's most substantial budget in years: www.policyengine.org/uk/autumn-bu...
/plugin marketplace add anthropics/claude-code
/plugin install frontend-design@claude-code-plugins
"use the frontend-design plugin to redesign our newsletter while sticking to the policyengine design principles"
/plugin install frontend-design@claude-code-plugins
"use the frontend-design plugin to redesign our newsletter while sticking to the policyengine design principles"
December 9, 2025 at 3:59 AM
/plugin marketplace add anthropics/claude-code
/plugin install frontend-design@claude-code-plugins
"use the frontend-design plugin to redesign our newsletter while sticking to the policyengine design principles"
/plugin install frontend-design@claude-code-plugins
"use the frontend-design plugin to redesign our newsletter while sticking to the policyengine design principles"
We built GiveCalc because most donation calculators just multiply by your tax bracket. That misses a lot: standard vs. itemized thresholds, state taxes, future-dated policy, new HR1 provisions.
PolicyEngine's tax models handle the full complexity. GiveCalc makes them accessible.
PolicyEngine's tax models handle the full complexity. GiveCalc makes them accessible.
This Giving Tuesday: GiveCalc is live at givecalc.org
A free PolicyEngine calculator showing how charitable donations affect your taxes.
🇺🇸 Federal + state tax savings (all 50 states)
🇬🇧 UK Gift Aid relief (including Scotland)
Know the true cost of giving → givecalc.org
A free PolicyEngine calculator showing how charitable donations affect your taxes.
🇺🇸 Federal + state tax savings (all 50 states)
🇬🇧 UK Gift Aid relief (including Scotland)
Know the true cost of giving → givecalc.org
GiveCalc - Charitable Donation Tax Calculator
Calculate how charitable giving affects your taxes. Powered by PolicyEngine.
givecalc.org
December 2, 2025 at 9:48 PM
We built GiveCalc because most donation calculators just multiply by your tax bracket. That misses a lot: standard vs. itemized thresholds, state taxes, future-dated policy, new HR1 provisions.
PolicyEngine's tax models handle the full complexity. GiveCalc makes them accessible.
PolicyEngine's tax models handle the full complexity. GiveCalc makes them accessible.
Important read on fiscal transparency.
While CBO is taking commendable steps by expanding its GitHub presence, Rauh & Jaros are right: full replicability should be the standard for them and JCT.
Open source builds trust and accuracy. www.wsj.com/opinion/the-...
While CBO is taking commendable steps by expanding its GitHub presence, Rauh & Jaros are right: full replicability should be the standard for them and JCT.
Open source builds trust and accuracy. www.wsj.com/opinion/the-...
Opinion | The CBO’s Numbers Must Be Made Public and Checkable
The budget watchdog’s models, data and assumptions are too important to leave hidden in a bureaucratic ‘black box.’
www.wsj.com
November 28, 2025 at 9:19 PM
Important read on fiscal transparency.
While CBO is taking commendable steps by expanding its GitHub presence, Rauh & Jaros are right: full replicability should be the standard for them and JCT.
Open source builds trust and accuracy. www.wsj.com/opinion/the-...
While CBO is taking commendable steps by expanding its GitHub presence, Rauh & Jaros are right: full replicability should be the standard for them and JCT.
Open source builds trust and accuracy. www.wsj.com/opinion/the-...
Great to see Rep Tlaib's team use PolicyEngine to design her new policy reform.
In a new article for People's Policy Project, @dtrim99.bsky.social used PolicyEngine to estimate the impact of @reprashida.govpeeps.us's Economic Dignity for All Agenda, finding the cash assistance package would (in 2026):
* Reduce poverty by 42%
* Lower the Gini index by 8.1%
* Cost $685 billion
* Reduce poverty by 42%
* Lower the Gini index by 8.1%
* Cost $685 billion
November 22, 2025 at 1:28 AM
Great to see Rep Tlaib's team use PolicyEngine to design her new policy reform.
I had a blast making this with Claude Code - both the animation and the spooky soundtrack, which it composed in Python.
github.com/policyengine...
github.com/policyengine...
October 31, 2025 at 10:35 PM
I had a blast making this with Claude Code - both the animation and the spooky soundtrack, which it composed in Python.
github.com/policyengine...
github.com/policyengine...
Our AI journey continues - excited to share our Claude Code plugin soon!
We tested whether Claude Code's multi-agent system could automate parts of policy research.
Three specialized agents handled data fetching, script writing, and report generation. Here's what we learned: policyengine.org/uk/research/...
Three specialized agents handled data fetching, script writing, and report generation. Here's what we learned: policyengine.org/uk/research/...
Testing multi-agent AI workflows for policy research | PolicyEngine UK
A multi-agent Claude Code system fared better on distributional analysis than benefit interactions; insights inform our forthcoming plugin.
policyengine.org
October 30, 2025 at 1:06 PM
Our AI journey continues - excited to share our Claude Code plugin soon!
Something about being in California brings out the ballot measure analyst in me!
California's proposed billionaire tax creates marginal rates of 50-60% on wealth between $1.0-$1.1 billion due to its phase-in structure. We analyzed the math behind Initiative 25-0024: policyengine.org/us/research/...
Marginal tax rates in California's proposed billionaire tax | PolicyEngine US
The 5% tax creates marginal tax rates between 50% and 60% on wealth between $1 billion and $1.1 billion.
policyengine.org
October 25, 2025 at 11:39 PM
Something about being in California brings out the ballot measure analyst in me!
Heading to LA this week for Benefit Navigator's event.
Their platform helps families and case managers navigate public benefits and tax credits - powered by the @us.policyengine.org API for tax and benefit calculations. Excited to see tech and policy come together to expand access.
Their platform helps families and case managers navigate public benefits and tax credits - powered by the @us.policyengine.org API for tax and benefit calculations. Excited to see tech and policy come together to expand access.
October 18, 2025 at 8:06 PM
Heading to LA this week for Benefit Navigator's event.
Their platform helps families and case managers navigate public benefits and tax credits - powered by the @us.policyengine.org API for tax and benefit calculations. Excited to see tech and policy come together to expand access.
Their platform helps families and case managers navigate public benefits and tax credits - powered by the @us.policyengine.org API for tax and benefit calculations. Excited to see tech and policy come together to expand access.
Tomorrow evening I'll be celebrating the 13th anniversary of the @opengovhub.bsky.social, @us.policyengine.org's new home in DC. I'll also give a short talk on our work to promote open governance and transparency, the mission of the space and our neighbor organizations. Tickets still available!
13th Anniversary Celebration of the Open Gov Hub
Celebrate 13 years of Open Gov Hub!
www.eventbrite.com
October 17, 2025 at 1:08 AM
Tomorrow evening I'll be celebrating the 13th anniversary of the @opengovhub.bsky.social, @us.policyengine.org's new home in DC. I'll also give a short talk on our work to promote open governance and transparency, the mission of the space and our neighbor organizations. Tickets still available!
Disappointed that the plant-based Shouk, my favorite fast-casual place in DC, has closed. Anti-Israel groups targeted it because an Israeli immigrant owned it, and are now cheering their victory.
October 7, 2025 at 12:03 PM
Disappointed that the plant-based Shouk, my favorite fast-casual place in DC, has closed. Anti-Israel groups targeted it because an Israeli immigrant owned it, and are now cheering their victory.
Agentic AI coding tools continue to inspire us to turn everything into software.
Join us at our new home in downtown DC, the @opengovhub.bsky.social, for a celebratory happy hour on Oct 22: luma.com/lnrzph2h
Join us at our new home in downtown DC, the @opengovhub.bsky.social, for a celebratory happy hour on Oct 22: luma.com/lnrzph2h
October 7, 2025 at 12:01 PM
Agentic AI coding tools continue to inspire us to turn everything into software.
Join us at our new home in downtown DC, the @opengovhub.bsky.social, for a celebratory happy hour on Oct 22: luma.com/lnrzph2h
Join us at our new home in downtown DC, the @opengovhub.bsky.social, for a celebratory happy hour on Oct 22: luma.com/lnrzph2h
Our new ACA calculator shows how extending the enhanced premium tax credits would affect households.
An extreme case: A 64-year-old in Fairbanks, AK would gain $655 in 2026 if they earn $61k, but gain $26,861 if they earn $62k.
Try it here: policyengine.org/us/aca-calc
An extreme case: A 64-year-old in Fairbanks, AK would gain $655 in 2026 if they earn $61k, but gain $26,861 if they earn $62k.
Try it here: policyengine.org/us/aca-calc
October 2, 2025 at 8:52 AM
Our new ACA calculator shows how extending the enhanced premium tax credits would affect households.
An extreme case: A 64-year-old in Fairbanks, AK would gain $655 in 2026 if they earn $61k, but gain $26,861 if they earn $62k.
Try it here: policyengine.org/us/aca-calc
An extreme case: A 64-year-old in Fairbanks, AK would gain $655 in 2026 if they earn $61k, but gain $26,861 if they earn $62k.
Try it here: policyengine.org/us/aca-calc
Come by tonight if you're in London!
Economic policy drinks tomorrow in London 🍺
Thursday 6-8pm at The Sherlock Holmes (Northumberland St, near Embankment)
Light bites + first round on PolicyEngine. Come meet economists & policy analysts working on UK tax/benefits/public finance.
luma.com/oz1qt2ec
Thursday 6-8pm at The Sherlock Holmes (Northumberland St, near Embankment)
Light bites + first round on PolicyEngine. Come meet economists & policy analysts working on UK tax/benefits/public finance.
luma.com/oz1qt2ec
Economic policy happy hour · Luma
Drinks and discussion for the UK economic policy community.
PolicyEngine is hosting an informal happy hour for economists, researchers, and policy analysts…
luma.com
October 2, 2025 at 8:51 AM
Come by tonight if you're in London!
The Prenatal-to-3 Policy Impact Center just launched their new Policy Impact Calculator, which uses @us.policyengine.org for federal and state tax modeling. Great example of research infrastructure enabling better policy decisions for young children and families.
pn3policy.org/policy-impac...
pn3policy.org/policy-impac...
2025 Policy Impact Calculator - Prenatal-to-3 Policy Impact Center
Explore our new interactive calculator to see how wages, paid leave, nutrition programs, child care subsidies, and tax credits shape the financial resources available to families with young children—s...
pn3policy.org
October 2, 2025 at 8:49 AM
The Prenatal-to-3 Policy Impact Center just launched their new Policy Impact Calculator, which uses @us.policyengine.org for federal and state tax modeling. Great example of research infrastructure enabling better policy decisions for young children and families.
pn3policy.org/policy-impac...
pn3policy.org/policy-impac...
Enjoyed my conversation with the SVIC Podcast about how
@policyengine.org uses Claude Code to democratize economic policy analysis. Watch here: youtu.be/4apWdJR9-iY?...
@policyengine.org uses Claude Code to democratize economic policy analysis. Watch here: youtu.be/4apWdJR9-iY?...
How A Google Engineer Uses Claude Code At His Startup - Max Ghenis Founder of Policy Engine
YouTube video by SVIC Podcast
youtu.be
September 18, 2025 at 9:11 AM
Enjoyed my conversation with the SVIC Podcast about how
@policyengine.org uses Claude Code to democratize economic policy analysis. Watch here: youtu.be/4apWdJR9-iY?...
@policyengine.org uses Claude Code to democratize economic policy analysis. Watch here: youtu.be/4apWdJR9-iY?...
Can't wait for our first live event in London! If you're in the area and interested in policy simulation, I think you'll discover major new possibilities our new app and research will offer.
See you there: eventbrite.co.uk/e/policyengi...
See you there: eventbrite.co.uk/e/policyengi...
September 13, 2025 at 10:42 PM
Can't wait for our first live event in London! If you're in the area and interested in policy simulation, I think you'll discover major new possibilities our new app and research will offer.
See you there: eventbrite.co.uk/e/policyengi...
See you there: eventbrite.co.uk/e/policyengi...
We constructed fully synthetic firm microdata to conduct this analysis. I was struck how calibrating to a large range of coarse aggregates could result in microdata that reveals sharp responses to cliff effects.
You could run a bunching study on this synthetic data! (And we will.)
You could run a bunching study on this synthetic data! (And we will.)
September 10, 2025 at 2:03 AM
We constructed fully synthetic firm microdata to conduct this analysis. I was struck how calibrating to a large range of coarse aggregates could result in microdata that reveals sharp responses to cliff effects.
You could run a bunching study on this synthetic data! (And we will.)
You could run a bunching study on this synthetic data! (And we will.)
This partnership exemplifies why we built PolicyEngine: policy analysis tools should be open, accessible, and sustainable.
Honored that NBER trusts us to ensure TAXSIM—the foundation of tax research for decades—continues serving researchers while evolving for modern needs.
Honored that NBER trusts us to ensure TAXSIM—the foundation of tax research for decades—continues serving researchers while evolving for modern needs.
🤝 Big news: PolicyEngine and @nber.org
have signed an MOU to ensure researchers worldwide continue accessing critical tax microsimulation tools.
We're building an open-source TAXSIM emulator, combining NBER's 50+ years of tax expertise with modern open-source infrastructure.
have signed an MOU to ensure researchers worldwide continue accessing critical tax microsimulation tools.
We're building an open-source TAXSIM emulator, combining NBER's 50+ years of tax expertise with modern open-source infrastructure.
September 5, 2025 at 7:37 PM
This partnership exemplifies why we built PolicyEngine: policy analysis tools should be open, accessible, and sustainable.
Honored that NBER trusts us to ensure TAXSIM—the foundation of tax research for decades—continues serving researchers while evolving for modern needs.
Honored that NBER trusts us to ensure TAXSIM—the foundation of tax research for decades—continues serving researchers while evolving for modern needs.
Today, @telegraphnews.bsky.social suggested that raising the UK VAT registration threshold would increase revenues in the long run. This misread (poorly documented) government projections, which reflected inflation adjustments in the baseline. My latest:
substack.com/home/post/p-...
substack.com/home/post/p-...
VAT thresholds, revenues, and the role of counterfactuals
No, the OBR has not projected that raising the VAT threshold would increase tax revenues.
substack.com
August 30, 2025 at 5:43 PM
Today, @telegraphnews.bsky.social suggested that raising the UK VAT registration threshold would increase revenues in the long run. This misread (poorly documented) government projections, which reflected inflation adjustments in the baseline. My latest:
substack.com/home/post/p-...
substack.com/home/post/p-...
I've been using Claude Code a LOT lately ($5,800+ in tokens last month on my $200 Claude Max plan), and now experimenting with custom slash commands and subagents. Here's an example: using parallel subagents to independently write integration tests and encode policies for @us.policyengine.org.
August 28, 2025 at 12:21 PM
I've been using Claude Code a LOT lately ($5,800+ in tokens last month on my $200 Claude Max plan), and now experimenting with custom slash commands and subagents. Here's an example: using parallel subagents to independently write integration tests and encode policies for @us.policyengine.org.
Reposted by Max Ghenis
🎉 PolicyEngine has been awarded a $300,000 Phase I POSE grant from NSF (Award No. 2518372) to expand our open-source platform, build sustainable governance, and grow our contributor community! https://policyengine.org/us/research/nsf-pose-phase-1-grant
National Science Foundation awards PolicyEngine $300,000 grant | PolicyEngine US
NSF's Pathways to Enable Open-Source Ecosystems program will support PolicyEngine's work to expand access to policy analysis tools.
policyengine.org
August 22, 2025 at 2:37 AM
🎉 PolicyEngine has been awarded a $300,000 Phase I POSE grant from NSF (Award No. 2518372) to expand our open-source platform, build sustainable governance, and grow our contributor community! https://policyengine.org/us/research/nsf-pose-phase-1-grant
Bumping the cap to $62k/124k would benefit 22% of US residents in the top income decile and 1.2% of those in the bottom 90%.
May 16, 2025 at 9:19 AM
Bumping the cap to $62k/124k would benefit 22% of US residents in the top income decile and 1.2% of those in the bottom 90%.
The SALT cap would raise taxes on 22% of Americans in the top income decile, and 3% of Americans in the bottom nine deciles.
May 14, 2025 at 11:57 PM
The SALT cap would raise taxes on 22% of Americans in the top income decile, and 3% of Americans in the bottom nine deciles.
Chatted with @kimberlyadams.bsky.social of @marketplace.org about the Ways & Means draft to extend 2017 individual tax cuts. The full bill is now out—SALT tweak, tip & OT deductions, and more. Crunching the numbers in @us.policyengine.org—stay tuned for results. 🎧 www.marketplace.org/story/2025/0...
www.marketplace.org
May 13, 2025 at 11:56 AM
Chatted with @kimberlyadams.bsky.social of @marketplace.org about the Ways & Means draft to extend 2017 individual tax cuts. The full bill is now out—SALT tweak, tip & OT deductions, and more. Crunching the numbers in @us.policyengine.org—stay tuned for results. 🎧 www.marketplace.org/story/2025/0...