Abstract
President Trump’s decision to move his official state of residence from high-tax New York to no (income)-tax Florida has brought public attention to an issue that has long troubled scholars, designers and administrators of income tax systems: how the interaction of tax rules deferring the taxation of income and tax rules based on residency allows taxpayers to reduce and even avoid taxation of their deferred income. These discontinuities in tax treatment may lead to excessive migration, as well as reductions in state income tax revenues and distortions in the design of state taxing mechanisms. This Article explains what states would have to do to eliminate these avoidance opportunities. However, it also points out that many of these policy changes would create other tax discontinuities. Ultimately, it leaves open the question whether making any of these changes would lead to fewer financial and behavioral distortions.