[runlevel1]

NBER's biggest contributors are the US government. Ironically, the IRS isn't one of them.[1]

As an aside, I'd love to see US gov research grants start requiring the work product to be made open source.

[1]: https://www.nber.org/about-nber/support-funding

[MaxGhenis]

Agreed. We're building an open source version of taxsim (plus benefit rules) at https://github.com/policyengine/openfisca-us.