Between 2020 and 2029, the IRS will fail to collect nearly $7.5 trillion of taxes it is due. It is not possible to calculate with precision how much of this “tax gap” could be collected. This paper offers a naïve approach. The analysis suggests that with feasible changes in policy, the IRS could aspire to shrink the tax gap by around 15 percent in the next decade—generating over $1 trillion in additional revenue by performing more audits (especially of high-income earners), increasing information reporting requirements, and investing in information technology. These investments will increase efficiency and are likely to be very progressive.
NBER Working Paper No. 26475 with Natasha Sarin, Lawrence H. Summers