Congressional report finds higher tax rates don't hurt growth, so Republican party has it pulled

"Changes in the top marginal tax rate do not appear correlated with growth."

The Republican congressional leadership. Photograph: Getty Images

A new report from the US's Congressional Research Service has been suppressed by Republicans after it concluded that tax rates are uncorrelated with economic growth or saving, investment, and productivity growth – but do affect the extent of income inequality in the nation.

The report concludes:

The top income tax rates have changed considerably since the end of World War II. Throughout the late-1940s and 1950s, the top marginal tax rate was typically above 90%; today it is 35%. Additionally, the top capital gains tax rate was 25% in the 1950s and 1960s, 35% in the 1970s; today it is 15%. The average tax rate faced by the top 0.01% of taxpayers was above 40% until the mid-1980s; today it is below 25%. Tax rates affecting taxpayers at the top of the income distribution are currently at their lowest levels since the end of the second World War.

The results of the analysis suggest that changes over the past 65 years in the top marginal tax rate and the top capital gains tax rate do not appear correlated with economic growth. The reduction in the top tax rates appears to be uncorrelated with saving, investment, and productivity growth. The top tax rates appear to have little or no relation to the size of the economic pie.

However, the top tax rate reductions appear to be associated with the increasing concentration of income at the top of the income distribution. As measured by IRS data, the share of income accruing to the top 0.1% of U.S. families increased from 4.2% in 1945 to 12.3% by 2007 before falling to 9.2% due to the 2007-2009 recession. At the same time, the average tax rate paid by the top 0.1% fell from over 50% in 1945 to about 25% in 2009. Tax policy could have a relation to how the economic pie is sliced—lower top tax rates may be associated with greater income disparities.

The report is particularly important for its treatment of capital gains tax as well as just income tax. The former is significantly lower than the latter, and has been for all but three years of the US's post-WWII history. As a result, it is a significant avenue for tax avoidance.

The argument for keeping capital gains tax low is that it stimulates investment, by encouraging people to invest rather than spend income. If, as the report concludes, it is in fact unconnected with investment rates, then that method of tax-dodging could be closed without harming the economy much, if at all.

The report, which was written by a neutral government body, was not welcomed by the Republican party, which is opposed to much taxation. The New York Times' Jonathan Weisman writes:

Senate Republican aides said they had protested both the tone of the report and its findings. Aides to Mr. McConnell presented a bill of particulars to the research service that included objections to the use of the term “Bush tax cuts” and the report’s reference to “tax cuts for the rich,” which Republicans contended was politically freighted.

They also protested on economic grounds, saying that the author, Thomas L. Hungerford, was looking for a macroeconomic response to tax cuts within the first year of the policy change without sufficiently taking into account the time lag of economic policies. Further, they complained that his analysis had not taken into account other policies affecting growth, such as the Federal Reserve’s decisions on interest rates.

“There were a lot of problems with the report from a real, legitimate economic analysis perspective,” said Antonia Ferrier, a spokeswoman for the Senate Finance Committee’s Republicans. “We relayed them to C.R.S. It was a good discussion. We have a good, constructive relationship with them. Then it was pulled.”