The Tax Cut Delusion

Economist Christina Romer on "supply side" tax-cut theories:

Since World War II, the top rate has ranged from less than 30 percent (at the end of the Reagan presidency) to more than 90 percent (throughout the Eisenhower years). The 1964 Kennedy-Johnson tax cut significantly reduced the typical marginal rate paid by American families, but rates rose greatly over the next 15 years as inflation pushed people into higher tax brackets. Rates fell sharply under President Reagan, rose under President Bill Clinton and fell again under President George W. Bush.

If you can find a consistent relationship between these fluctuations and sustained economic performance, you’re more creative than I am. Growth was indeed slower in the 1970s than in the ’60s, and tax rates were higher in the ’70s. But growth was stronger in the 1990s than in the 2000s, despite noticeably higher rates in the ’90s...

I can’t say marginal rates don’t matter at all... But the strong conclusion from available evidence is that their effects are small. This means policy makers should spend a lot less time worrying about the incentive effects of marginal rates and a lot more worrying about other tax issues.

Most obviously, the federal budget is on a collision course with reality. Reining in the long-run deficit will have to involve slowing the growth rate of spending. But unless we choose to gut Medicare and Medicaid, additional tax revenue will be needed. This essential truth is the No. 1 factor that should be driving tax policy. And anyone who tells you that the way to raise revenue is to cut marginal tax rates is arguing from ideology, not solid evidence.