Net Present Value of the Billionaire Tax Act

This repository contains replication materials for

"The Net Present Value of the Billionaire Tax Act" (2026). Rauh, Jaros, Kearney, Doran, Cosso. SSRN

Structure

• NPV_data/ -- R scripts, input data, and simulation output.
• NPV_plots/ -- Figures (PDF and PNG) generated by the scripts.

Replication Guide

Both scripts are self-contained R files. To replicate:

1. Install dependencies. The scripts require dplyr, ggplot2, and ggthemes.

   install.packages(c("dplyr", "ggplot2", "ggthemes"))

2. Set the working directory. Open each script and update the setwd() call at the top to point to your local clone of this repository.

3. Run the scripts. From NPV_data/:

   Script	Paper Section	Description	Outputs
   monte_carlo_sim.R	Section 5.1 -- Estimating Billionaire Income Tax Contributions	Fits a Pareto distribution to CA FTB filer data ($\hat{\alpha} = 1.44$) and runs 100,000 Monte Carlo draws to estimate the aggregate income tax liability of 212 billionaires across pool sizes K = 212 to 2,000. Produces Figure 2 and Table 1.	monte_carlo_results_v2.csv, billionaire_tax_monte_carlo_*.png/.pdf
   NPV_dist.R	Section 5.4 -- Distribution of Outcomes Across the Parameter Space	Draws 100,000 parameter combinations (WT ~ U[$35B, $67.5B], C ~ U[$3.3B, $5.8B], r ~ U[1.5%, 4.5%]) and computes the net present value of the Act for each draw. Produces Figure 3.	npv_distribution_*.png/.pdf

4. Input data. The Excel workbooks in NPV_data/ contain the underlying source data:

   • Raw_Data_Collection.xlsx -- Primary data collection.
   • NPV_calculations_5.2.xlsx -- Perpetuity valuation inputs (Section 5.2).
   • CA_Billionaires_Revenues_and_Migration_final.xlsx -- California billionaire revenue and migration estimates.

Mapping to Paper

Paper Section	Content	Replication Materials
5.1 Estimating Billionaire Income Tax Contributions	Pareto fit to FTB data; Monte Carlo simulation of billionaire income tax liability ($3.3--5.8B)	monte_carlo_sim.R, monte_carlo_results_v2.csv
5.2 Perpetuity Valuation of Income Tax Collections	Present value framework under varying discount rates and departure scenarios	NPV_calculations_5.2.xlsx
5.3 Net Present Value by Departure Scenario	NPV across three departure scenarios and three discount rates (Table 3)	NPV_calculations_5.2.xlsx
5.4 Distribution of Outcomes Across the Parameter Space	100,000-draw simulation; 71% of draws yield negative NPV (mean = -$24.7B)	NPV_dist.R, npv_distribution_*.png/.pdf

Disclaimer

The views expressed in this paper are those of the authors and do not necessarily reflect the views of any affiliated institutions. This repository is provided for replication and transparency purposes only.

License

This project is licensed under the MIT License.