“The feds assume a relationship between the economy and tax revenue that is divorced from reality. Six decades of history have established one far-reaching fact that needs to be built into fiscal calculations: Increases in federal tax rates, particularly if targeted at the higher brackets, produce no additional revenue… a ratio of federal revenue to GDP of no more than 18.3% would be realistic.” – David Ranson, Wall Street Journal.

…..full article HERE

Average federal revenues, as % of GDP, over various periods:

1950-59:  17.2%

1960-69:  17.9%

1970-79:  17.9%

1980-89:  18.3%

1990-99:  18.6%

1960-2000:  18.2%

2000-08:  18.2%