Scheduled for the IIPF Annual Meeting 2026.
Abstract
Despite broad public support for progressive taxation, the current U.S. tax system is among the most regressive in history. This paper tests whether social and institutional ties between legislators and the ultra-rich help explain this mismatch. We use large language models to classify the progressivity of the full universe of tax-related bills introduced in Congress since 1973. Using publicly available biographies, we then construct a new dataset linking Members of Congress to billionaires through overlap in higher-education institution, program, and graduation cohort. Our preliminary findings suggest that legislators with greater exposure to billionaires during college and university are more likely to sponsor regressive tax proposals and fewer progressive ones. These results support the view that elite networks can transmit political influence through informal social channels.