Third parties solve
Saez 19, Professor @ University of California, Berkeley, with Gabriel Zucman, Professor @ University of California, Berkeley (Emmanuel, “Progressive Wealth Taxation,” Brookings, https://www.brookings.edu/wp-content/uploads/2019/09/Saez-Zucman_conference-draft.pdf)//BB
The key to successful modern income taxation is information reporting by third parties such as employers and financial institutions (Kleven et al. 2011). This reporting allows the tax administration to get direct information on most income sources so that self-reporting is reduced to a minimum. The same principle should be followed for the wealth tax. Taxpayers and the IRS would receive information returns from financial institutions showing the value of their assets at the end of the year. For administrative success, it is essential that such third-party reporting cover the widest possible set of assets and debts (just as the income tax is most successfully enforced on the types of income with third-party reporting). A wealth tax also requires policies regarding information reporting, the valuation of assets, the treatment of trusts, among other design considerations. We discuss these below.