PolicyEngine is a nonprofit with the mission to compute the impact of public policy for the world.

Our free, open-source software models the tax and benefit systems in the US and UK, using our microsimulation framework based on OpenFisca, enhances representative survey microdata for macroeconomic analysis, and makes those available as Python packages, APIs, or web apps. The PolicyEngine web app lets users design custom tax-benefit reforms and see how they would affect the population (budget, poverty, and inequality) and individual households (net income and marginal tax rates). Users can also skip the policy reform and estimate their tax liability and benefit eligibility under current law.

We welcome contributions to our repositories, especially our core ones:

• policyengine-us, the US tax-benefit microsimulation model (Python)
• policyengine-uk, the UK tax-benefit microsimulation model (Python)
• policyengine-canada, the Canada tax-benefit microsimulation model (Python - EARLY)
• policyengine-app, the app client (React)
• policyengine-api, the REST API (Python)
• policyengine-core, the microsimulation framework (Python)