Enforcement effectively prevents invasion
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
Wealth concealment is a serious enforcement concern. However, just like for legal avoidance, illegal evasion depends on policies and can be reduced through proper enforcement. Key to reducing evasion are (i) the collection of comprehensive data; (ii) sanctions for the suppliers of tax evasion services (the countries and financial intermediaries that facilitate it); (iii) proper resources for auditing. In terms of data collection, the United States has taken an ambitious path forward with the 2010 Foreign Account Tax Compliance Act (FATCA) that requires all foreign financial institutions to identify and report their U.S. customers to the IRS.