"Consider: The economy grew at 3.9 percent from 1950 to 1970, when the average top marginal income tax rate was 84.8 percent. From 1987 to 2010, when the average rate was less than half that (36.4 percent), economic growth was far less robust, 2.9 percent.
This comparison might be misleading because multiple factors affect the economy, so the CRS looked at a shorter, more recent time span.
From 1987 through 1992, the top average marginal income tax rate was 33.3 percent. Economic growth averaged 2.3 percent.
From 1993 through 2002, after taxes increased under President Clinton, the average top marginal rate was 39.5 percent. Economic growth averaged 3.7 percent.
Finally, from 2003 through 2007, after the Bush tax cuts, the average top marginal rate was 35 percent. Economic growth averaged 2.8 percent.
If you were going to make a causality argument from these figures, it would be that lower taxes correlate with lower growth. Such a leap isn’t justified — but where is the proof supporting Republicans’ insistence that lower rates fuel growth?"
How about that?