Formulary Apportionment in the U.S. International Income Tax System: Putting Lipstick on a Pig?

Abstract

Perhaps surprisingly, this Article has shown that the debate over formulary apportionment is little more than an alternative path to the larger debate over worldwide taxation versus territorial taxation. The present U.S. international income tax regime for U.S. MNEs is an implicit, overly-generous, and incoherent quasi-territorial system that relies on residence rules, source rules, and the arm’s-length approach to apportion international business profits between domestic income that is currently taxable by the United States and foreign income that is effectively exempt, or nearly so, from U.S. taxation because of deferral and cross-crediting. This version of territoriality is quite ugly because it is highly complex and it imposes only modest restraints on the ability of U.S. MNEs to shift income out of the U.S. tax base to low-tax foreign countries.

Four forms of explicit territoriality have been proposed as alternatives to the current U.S. system. The first is traditional territoriality, which relies on source rules and the arm’s-length approach to apportion international business profits between taxable domestic income and exempt foreign income. This is a simpler regime than the current U.S. system because it confers exemption directly rather than implicitly through deferral and cross-crediting. It does, however, preserve the capacity of taxpayers to shift income to low-tax foreign countries subject only to the modest restraint imposed by the arm’s-length approach. Most importantly, it is inconsistent with the principle of ability-to-pay and it provides a powerful incentive to locate business activity in low-tax foreign countries.

The other three forms of territoriality that are currently part of the debate are three-factor, two-factor, and single-factor global formulary apportionment. Each of them is simpler than either the current U.S. system or traditional territoriality, but each of them leaves U.S. MNEs with considerable capacity to accomplish erosion of the U.S. tax base through income shifting and each of them shares the defects of traditional territoriality regarding inconsistency with the ability-to-pay principle and distortion of business activity. Thus, U.S. policy makers are left with a choice between a normatively flawed and distortive territoriality that imposes modest restraints on income shifting through the arm’s-length approach (i.e., both the current U.S. system of de facto territoriality and traditional territoriality) and a simpler but normatively flawed and distortive territoriality that still allows a substantial amount of income shifting (i.e., three-factor, two-factor, and single-factor global formulary apportionment). This unhappy dilemma can be avoided by adopting real worldwide taxation or, alternatively, by keeping the current regime while creating a Subpart F income category for low-taxed foreign income and insulating that category from cross-crediting with a separate foreign tax credit limitation basket. A more limited form of formulary apportionment then should be used for, and tailored to, particular forms of income, such as intangible income and global trading income, that present discrete taxation problems. Nevertheless, when such income is earned by a U.S. MNE, allocation of income to a foreign jurisdiction under this more limited form of formulary apportionment should not ipso facto result in the income being exempted from U.S. taxation.