Is the Haig‐Simons Standard Dead? The Uneasy Case for a Comprehensive Income Tax

Discussions of the "ideal" form of individual income taxation have largely been based on some variant of the standard suggested by Haig (1921) and Simons (1938). This "Haig‐Simons" (H‐S) standard argues that an ideal income tax should be imposed on "comprehensive income," and the H‐S standard has been used to justify the frequently heard call for a "Broad-based, Low-rate" tax reform strategy. However, I argue in this paper that a truly comprehensive individual income tax has in fact never been fully applied, either in the design of a new income tax or in the reform of an existing one. Indeed, my first conclusion is that the H‐S standard is effectively "dead" in terms of its actual real-world relevance to income tax design or reform. This conclusion obviously does not demonstrate that the H‐S standard should be discarded as the basis for an ideal individual income tax, including any reform of the income tax. However, my second conclusion is that the "death" of the H‐S standard is entirely appropriate; that is, there are compelling arguments that can be made for an individual income tax that is in fact imposed on an even narrower tax base, with even more extensive use of the many exclusions, adjustments, deductions, and exemptions that currently populate most all income taxes. Even so, my final conclusion is that there is no one-size-fits-all income tax standard; that is, any standard must consider the specifics of the current environment, especially the underlying goals of taxation.