Billionaire Taxes and the Constitution

The United States now has ten times as many billionaires as it had just a few decades ago. This ever-growing class has sparked congressional interest in “billionaire tax” proposals. These proposals would generally require that billionaires recognize income when their asset values increase, even if they have not sold their assets. Under existing doctrine, billionaire taxes likely violate the realization requirement embedded in the Sixteenth Amendment of the Constitution. However, this Article argues that existing Sixteenth Amendment doctrine suffers from deep infirmities and theoretical inconsistencies. With the conceptually sound interpretive approach advanced in this Article, a billionaire tax could pass constitutional muster