I also like the flat tax because it gets rid of all deductions, credits, exemptions, preferences, exclusions, and other distortions. And a loophole-free tax code would be a great way of reducing Washington corruption and promoting simplicity.
Moreover, keep in mind that eliminating all favors from the internal revenue code also would be good for growth because people then will make decisions on the basis of what makes economic sense rather than because of peculiar quirks of the tax system.
Sounds great, right?
Well, it’s not quite as simple as it sounds because there’s a debate about how to measure loopholes. Sensible people want a tax code that’s neutral, which means the government doesn’t tilt the playing field. And one of the main implications of this benchmark is that the tax code shouldn’t create a bias against income that is saved and invested. In the world of public finance, this means they favor a neutral “consumption-base” tax system, but that’s simply another way of saying they want income taxed only one time.
Folks on the left, however, are advocates of a “Haig-Simons” tax system, which means they believe that there should be double taxation of all income that is saved and invested. You see this approach from the Joint Committee on Taxation. You see it from the Government Accountability Office. You see it from the Congressional Budget Office. Heck, you even sometimes see Republicans mistakenly use this benchmark.