September 28, 2017 2:57PM

Hidden Tax Hike in GOP Plan?

The Republican tax framework released yesterday was generally excellent. However, it appears to include a sneaky and invisible tax hike. The framework “envisions the use of a more accurate measure of inflation for purposes of indexing the tax brackets and other tax parameters.”

The individual income tax is indexed for inflation, meaning that the dollar split points between the rate brackets and other parameters are set to rise a bit each year. Without those adjustments, Americans would lose ground to the government over time, as more of their income would be taxed at higher rates due to the general rise in prices.

Current indexing is based on the Consumer Price Index (CPI). The CPI overstates inflation somewhat, so some analysts have suggested switching tax‐​code indexing to chained CPI, which produces a lower inflation measure.

If Republicans indexed the tax code to chained CPI, the government would receive an automatic tax increase relative to current law every year until the end of time. The Tax Foundation has a brief on the issue here.

Switching tax‐​code indexing to a lower measure of inflation is a bad idea for two reasons:

  • It would generate a substantial tax increase over time, and it would be an invisible increase because there would be no tax‐​filing changes for people to notice.
  • It would be an anti‐​growth tax increase because it would push people into higher brackets more quickly over time, subjecting them to higher marginal tax rates. The chained CPI proposal is essentially a proposal to slowly and steadily increase marginal tax rates.

Some economists may argue that the chained CPI proposal is a good idea because the tax code would more accurately reflect inflation, and it would. However, the tax code already contains a bias that pushes people into higher tax brackets over time, called “real bracket creep.” Real growth in the economy steadily moves taxpayers into higher rate brackets, since the tax code is indexed for inflation but not real growth.

Long‐​range projections from the Congressional Budget Office reflect substantial increases in taxes over time from real bracket creep. The agency notes:

… if current laws remained generally unchanged, real bracket creep would continue to gradually push up taxes relative to income over the next three decades. That phenomenon occurs because most income tax brackets, exemptions, and other tax thresholds are indexed only to inflation. If income grows faster than inflation, as generally occurs when the economy is growing, tax receipts grow faster than income.

So, I’ve got a better idea than indexing the tax code to a “more accurate measure of inflation,” as Republicans are suggesting: indexing the tax code to nominal GDP growth. That would adjust for the effects of both inflation and real economic growth on tax‐​code parameters, and it would prevent stealth tax‐​rate increases under our graduated income tax system.

More on tax reform here, here, here, here, here, and here.