Support Us

Progressive Wealth Tax

A part of Senator Elizabeth Warren’s 2020 presidential platform is a progressive wealth tax on the net worth of American households, including a 2% tax on net worth above $50 million, and an additional 1% tax on net worth above $1 billion. The plan is based on a policy analysis by UC Berkeley economists Emmanuel Saez and Gabriel Zucman.

Through the Berkeley Initiative for Transparency in the Social Sciences (BITSS), we worked with Saez and Zucman to apply OPA to the analysis behind the proposal, and develop a suite of tools and materials to make the analysis fully reproducible. These include:

  1. An interactive plot, which summarizes the interactions between all key parameters (1.a) for a given set of assumptions (1.b).
  2. Open policy report in the form of a dynamic document, which details all data, code, and assumptions included in the analysis.
  3. Github repository, which stores all data, code, and materials necessary to replicate the analysis in full with minimal effort.

“Our analysis is fully transparent and reproducible, and we would love to see opposing arguments laid out in a similar way,” say Saez and Zucman. “To truly achieve the ideals of evidence-based policy, both policymakers and policy analysts need to be clear about what evidence they include in their reasoning, and how.”

This is the first collaborative case study in OPA, and it complies with the highest levels of the OPA Guidelines. Its purpose, in part, is to demonstrate tools and concepts through which OPA can be implemented in practice. This and future case studies  will inform the continued development of the Guidelines.

If you would like to collaborate with BITSS to develop a demonstration of OPA in your organization or a particular policy report, please email Aleks Bogdanoski (

Share Now

Copyright 2024. All Rights Reserved

Design & Dev by Wonderland Collective