By contrast, the Tax Foundation numbers are nothing more or less than a compilation and tabulation of RAW IRS DATA. That report involves NO projections, assumptions or hypothesis. That data table does not attempt to interpret the numbers, nor make allowances. As Sgt. Joe Friday would say, "Just the facts." Anyone with a calculator and a FOI Act Request Form could easily come up with the same numbers and, in fact, would be hard pressed to come up with different numbers.
Also, take a look at the funding of both organizations. The Brookings Institution is funded almost entirely by large grants and endowments from people and organizations that stand to benefit from high taxes and control of wealth. The Tax Foundation, though it does receive significant funds from endowments, is funded largely by small donation from the general public. The Board of Trustees of the Brookings Institution is loaded with many names of people who stand to benefit from high taxation and financial control, including several bright red flags, like the past and current Presidents of the World Bank. The Policy Council of the Tax Foundation contains the names of many powerful people - mostly corporate tax executives - but contains none of the red flags, such as those found sprinkled liberally among the Brookings Trustees. (Note: some of those red flags would not be red flags if we were not talking about taxes. But, you can't convince me that people like James D. Wolfensohn, President of The World Bank and Robert L. Johnson, founder and Chairman of BET Holdings, Inc., including Black Entertainment Network, are not in favor of high taxes and government control of wealth.)
I think that I would put my faith in the Tax Foundation tabulations long before I would consider giving any credence to the Brookings Institution interpretations and projections. Besides, you know what they say about people who have spent time in an institution. :-)